IP2M-841-V3: GotoPreset broken after firmware update

[sidamos]

I had this firmware:
Amcrest_IPC-Consumer-Mao-Molec_Eng_N_AMCREST_V2.800.0000000.3.R.191130.bin
Software VersionV2.800.0000000.3.R, Build Date: 2019-11-30

Then I upgraded to this:
Amcrest_IPC-Consumer-Web-Mao-Molec_Eng_N_AMCREST_V2.800.0000000.6.R.200314.bin
Software VersionV2.800.0000000.6.R, Build Date: 2020-03-14

I had 2 saved preset positions. Then I did a reset to Factory Default, setup the camera and imported my backup.

Settings are back, but GotoPreset does not work anymore. Tested the Amcrest Webinterface, the Android App and cgi-bin command:
http://192.168.0.18/cgi-bin/ptz.cgi?act ... 2=1&arg3=0
Error
Bad Request!

This command works fine with my backup camera.

Also tried adding a new preset and could not goto this one either.

So, I though that this new firmware version has a bug.

Installed the previous firmware, factory reset, import the backup.

Still goto preset does not work anymore!?

What can I do?

Edit:
Did again a factory reset and did NOT import my backup.
Presets do work now. Added 3 presets and goto works.
Imported my backup again and now presets 1 and 2 work again, but they go to the positions I saved last and not those from the backup!
So it seems, that import settings does not import the presets correctly or export does not export the presets correctly.

[sidamos]

Updated to the new firmware again, did factory reset, imported settings.
GotoPreset does not work.
Deleted presets and created new presets.
GotoPreset does work again.