Hello @Wolfgang_Schwarz,
Thank you for running that test. Since the issue does not appear when using 16-bits, I believe that you are likley seeing this XMOS issue:
We are in the process of contacting manufacturers regarding this issue and I will be sure to let you know once I have an update to share regarding this XMOS issue.
As for checking the logs to confirm, I have just looked up diagnostics mode on your account and it seems that our systems have not received any new reports from your machine. I have re-enabled this feature for your account but if the diagnostics still do not come in, can you please manually send them to us for review? The best way to get them over to us would be on a shared Dropbox or shared Google Drive link. If you do not have either services, let me know and I will provide an alternate upload method.
Please let me know if you are able to manually send us the logs for review and then we can confirm with better certainty that this is the issue you are experiencing.
Thanks,
Noris