It first fails here in building an SSL/TLS secure connection:
From the SIM7600 AT commands manual https://www.waveshare.com/w/upload/5/54/SIM7500_SIM7600_Series_AT_Command_Manual_V1.08.pdf :
From SSL Server Test (Powered by Qualys SSL Labs)
It fails at the first SSL connection and from all that, it would appear that the SIM7600 does not support the SSL/TLS level that the site community.beelogger.de permits.
Of course, the documentation for the SIM7600 could also be out of date. That may explain why others, with a similar module, have had apparent success.
EDIT
You should be able to use <CTRL> A in the serial monitor to highlight everything, <CTRL> C to copy it and <CTRL> X to paste it into the post.
I can't find the code which generates this (yellow parts). So you see anything in the code you modified to enhance the debugging level ?
