Need to Change FSSODet Line From AppointmentEntry Screen ( FS.30.02.00)

I have a strange problem. Due to a conflict (I guess) with a 3rd party vendor, my customer sometimes experiences very odd behavior. 

What happens is when they create an appointment from a service order, and save the appointment, it changes the UnitPrice on the Sales Order Detail.

I know that sounds weird… but, in example:

If line 3 of the sales order detail has a unitPrice of $20, and they add an appointment, its detail line 3 also shows a UnitPrice of $20. But when they save the appointment, the service order line 3 now has a price of $34.95. 

It doesn’t always happen. When it happens the price is not always the same amount. It’s not always the same inventory item. But it happens enough to be a problem.

Fortunately, we have a data set that, when following the same steps, will show the same problem every time. So I have to run it, roll it back, run it again, etc. Long process to debug, but at least it is repeatable.

That is why I know it has something to do with a conflict elsewhere. I can put a debugger on the RowInserting event, and the price is $20. At the start of RowInserted, it is still $20. But, coming out of RowInserted, it has inexplicitly changed. There is nothing in my code that changes it... It happens somewhere else. But, it does not happen if I unpublish my code. It also does not happen if I only publish my code.

So, unable to trace it to ground, I am trying a hack-y fix. When the appointment is entered, on the (Events.RowPersisted<FSAppointment> e) event, I want to check the unitPrice, correct it if necessary, and then save it back out with the correct value.

And, I want to save the changes by calling the pressSave event in the ServiceOrderEntry Graph, because it does total and tax calculations, and I don’t want to have to code all of that by hand.

I have code that runs fine, but the update is not working and I am at a loss as to why. Here is the code:

        protected virtual void _(Events.RowPersisted<FSAppointment> e, PXRowPersisted BaseHandler)
        {
            var accessScreen = base.Base.Accessinfo.ScreenID;

            var fsAppointmentDetCache = Base.Caches[typeof(FSAppointmentDet)];
            var fsSODetCache = Base.Caches[typeof(FSSODet)];
            // Acuminator disable once PX1045 PXGraphCreateInstanceInEventHandlers [Justification]
            if (serviceOrderGraph == null)
            {
                serviceOrderGraph = GetNewServiceOrderEntryGraph(clearGraph: true);
            }
            // Capture original values before any changes are persisted
            string onRefNbr = e.Row.SORefNbr;
            string onSoType = e.Row.SrvOrdType;
            FSServiceOrder onServiceOrder = FSServiceOrder.PK.Find(e.Cache.Graph, onSoType, onRefNbr);
            List<LinePrice> linePrices = new List<LinePrice>();
            foreach (FSSODet line in fsSODetCache.Cached)
            {
                LinePrice lp = new LinePrice
                {
                    LineNbr = line.LineNbr.Value,
                    Price = line.UnitPrice.GetValueOrDefault(),
                    SoType = onSoType,
                    RefNbr = onRefNbr
                };
                linePrices.Add(lp);
            }
            // ensure the Base method logic is executed:
            BaseHandler?.Invoke(e.Cache, e.Args);
            List<int?> ChangedLines = new List<int?>();
            foreach (LinePrice lp in linePrices)
            {
                // Find the corresponding FSSODet row based on LineNbr.
                FSSODet matchingDetail = PXSelect<FSSODet,
                    Where<FSSODet.srvOrdType, Equal<Required<FSSODet.srvOrdType>>,
                        And<FSSODet.refNbr, Equal<Required<FSSODet.refNbr>>,
                        And<FSSODet.lineNbr, Equal<Required<FSSODet.lineNbr>>>>>>
                    .Select(serviceOrderGraph, lp.SoType, lp.RefNbr, lp.LineNbr);
                serviceOrderGraph.ServiceOrderRecords.Current = onServiceOrder;

                if (matchingDetail != null && matchingDetail.UnitPrice != lp.Price)
                {
                    ChangedLines.Add(matchingDetail.LineNbr);
                    // If the prices are different, update the UnitPrice.
                    matchingDetail.UnitPrice = lp.Price;
                    serviceOrderGraph.ServiceOrderDetails.Cache.Update(matchingDetail);
                }
            }
            // Save changes after updating all necessary lines.
            // Acuminator disable once PX1043 SavingChangesInEventHandlers [Justification]
            serviceOrderGraph.Save.Press();
            // Confirm changes after updating all necessary lines.
            foreach (int? linnbr  in ChangedLines) 
            {
               var FSDetail = FSSODet.PK.Find(serviceOrderGraph, onSoType, onRefNbr, linnbr);
                if (FSDetail != null) 
                {
                   var chkPrice =  FSDetail.UnitPrice;
                    int i = 0;
                }
            }
        }

 It is a little wonky because I added some things in there for debugging. This code uses a simple class:

    internal class LinePrice
    {
        internal decimal? Price;
        internal int? LineNbr;
        internal String RefNbr;
        internal String SoType;

        public LinePrice() { }
    }

And I also copied GetServiceOrderEntry from the Acumatica source code to get the ability to create a ServiceOrderENtry graph from within AppointmentEnrty.

        internal ServiceOrderEntry GetNewServiceOrderEntryGraph(bool clearGraph)
        {
          ServiceOrderEntry _ServiceOrderEntryGraph = null;  // this will always make new

        if (_ServiceOrderEntryGraph == null)
        {
           _ServiceOrderEntryGraph = PXGraph.CreateInstance<ServiceOrderEntry>();
        }
        else if (clearGraph == true && _ServiceOrderEntryGraph.RunningPersist == false)
        {
           _ServiceOrderEntryGraph.Clear();
        }

        if (_ServiceOrderEntryGraph.RunningPersist == false)
        {
            _ServiceOrderEntryGraph.RecalculateExternalTaxesSync = true;
            _ServiceOrderEntryGraph.GraphAppointmentEntryCaller = this.Base;
        }

        return _ServiceOrderEntryGraph;
        }

Any help would be greatly appreciated. The only other thing I know to try is using PXDatabase.Update() -- which WILL update it, but then I have to code the totaling and tax totals myself which I REALLY don’t want to do.