Issues with migrating configuration from LCNC 2.8.3 buster to 2.9.3 bookworm

Hi,
I have a working configuration on LCNC 2.8.3 running on Buster. I would like to modernize so I'm trying to move to 2.9.3 bookworm. I figured I could just copy my existing configuration and run it, but that throws errors.
My configuration inserts a QtVCP window as additional tab in the Axis UI. Works great on 2.8.3. Now when I run that config on 2.9.3 I get two errors in separate windows. The first window is a QtVCP error window with the message:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/qtvcp/widgets/tab_widget.py", line 43, in tabSizeHint
    return QSize(size.width(), w)
           ^^^^^^^^^^^^^^^^^^^^^^
TypeError: arguments did not match any overloaded call:
  QSize(): too many arguments
  QSize(w: int, h: int): argument 2 has unexpected type 'float'
  QSize(a0: QSize): argument 1 has unexpected type 'int'

The second window is the LinuxCNC log (attached as file), where the problem line seems to be:

[QTvcp.QTVCP.WIDGETS.SCREEN_OPTIONS][[36mINFO[0m]  [32mInstalling Embedded tab:BaxEDM, default, halcmd loadusr -Wn qtvcp_embed qtvcp -d -c qtvcp_embed -x {XID} baxedm2[0m (screen_options.py:461)
[QTvcp.QTVCP.WIDGETS.SCREEN_OPTIONS][[33mWARNING[0m]  problem inserting VCP 'BaxEDM' to location: rightTab :
 'VCPWindow' object has no attribute 'rightTab' (screen_options.py:485)

Any ideas how to resolve this?

I installed the PyQt dev tools on this new 2.9.3 + bookworm PC and tried to open the *.ui file with the PyQt designer tool. It threw the same error. I can open this same ui file on my 2.8.3 + buster PC without any problems.
So something has changed in the toolchain that cannot deal with my "old" ui file.

In retrospect I should have started this tread in the PyQt section, but I cannot move it. If you are an admin, can you move it for me?

QTPyVCP would be the best match.

I fixed it, but probably not in the easiest way. I completely rebuild my *.ui file with the designer, but used the designer on the new pc instead. Screens look the same, use the same widgets and now the UI runs.
Loading a *.ui made on a older version apparently is not backwards compatible...

After the ui finally loaded I ran into other issues. Took me a while to find what was causing that. Turned out my existing python user scripts refused to run. To fix that the first line in the *.py files needed to be changed from:
#!/usr/bin/env python
to
#!/usr/bin/env python3
also I changed the rights to the python files with chmod u+x

After that the scripts ran without any problems.