Crash in IWForm.FillRealTabOrder - every 2-3 clicks

[Victoria]

Hello IntraWeb Team,
i got a nasty problem. My Server crashes every 2-3 clicks.
Every Time on the same Line. For understanding. I build many Items (IWButton/IWLink/...) dynamically and release them if needed.
So i can click around 1-3 times max without crash but after then it happens. I can not find out which problem he has with the list (FillRealTabOrders).
My components will generated at this way: Build the the New one. Give them the Settings from the old Control. Delete the old Control.
For this Tab i use:
  iMemTab := oOldCtrl.TabOrder;
  oOldCtrl.TabOrder := -1;
  oNewCtrl.TabOrder := iMemTab;


System:
Win10 64bit
Delphi 10.2.3
IntraWeb 15.2.3
StandAlone (HTTP.SYS)



Please help me - i think it is possible that in old intraweb version this problem not exists. But not sure.
with friendly regards
Victoria

-------------------EDIT
In he meanwhile i found out that OnClick seems to cause the trouble. So i switched everything to AsyncClick + (in old version from IntraWeb i could only generate a button before the FormCreate to replace that properly with my own IWButton Class) - now reworked this logic and dont replace the components. This seems to work but causes another Problem.
I has a TIWGrid what i fill with generic items (IWLabel, IWImageFile) and the TIWImageFile worked until my last changes. Exact this trouble i has got describe in the older Ticket here:
https://www.atozed.com/forums/thread-1445.html

But now - not only the first "row" (IWImageFile in the Control of a Row) doesn't work ... none of them does?! 
Maybe you can help me with the new problem.