@FamousL Have you investigate on Nextcloud forum about this issue ? I would suggest to first check on NC forum/ community section https://help.nextcloud.com/
@FamousL as go through all the possible solution and it might seems to be and issue with communication issue between NC and COOL.
I also encourage you if you can add a detailed note and file a GitHub issue ticket on this ?
Thank you for your amazing effort to describe the problem. Now a little help on filing the problem will also help to investigate and fix this problem
Thanks,
Darshan