Business Central craches when try to set purchase invoice to read only mode

[linasostr]

Business Central craches when try to set purchase invoice document to read only mode.

Issue happens when "Purch. Invoice Subform" is extended and another repeater is added for purchase lines:

Issue was recreated using Cronus database BC27.5 and following extension was deployed:

pageextension 50100 "Purch. Invoice Sub. Ext." extends "Purch. Invoice Subform"
{
    layout
    {
        addafter(PurchDetailLine)
        {
            repeater(S4LAPurchDetailLine)
            {
                field(S4LAFilteredTypeField; TypeAsText)
                {
                    ApplicationArea = All;
                    Caption = 'Type';
                    LookupPageID = "Option Lookup List";
                    TableRelation = "Option Lookup Buffer"."Option Caption" where("Lookup Type" = const(Purchases));
                    ToolTip = 'Specifies the type of transaction that will be posted with the document line. If you select Comment, then you can enter any text in the Description field, such as a message to a customer. ';
                }
            }
        }
    }
    trigger OnAfterGetRecord()
    begin
        UpdateTypeText();
    end;

    trigger OnAfterGetCurrRecord()
    begin
        UpdateTypeText();
    end;

    var
        TempOptionLookupBuffer: Record "Option Lookup Buffer" temporary;
        TypeAsText: Text[30];

    local procedure UpdateTypeText()
    var
        RecRef: RecordRef;
    begin
        RecRef.GetTable(Rec);
        TypeAsText := TempOptionLookupBuffer.FormatOption(RecRef.Field(Rec.FieldNo(Type)));
    end;
}

Attached video with the situation.

BC.craches.mp4