Which Files could be causing sync to crash Nextcloud?

Hi,

I am having difficulties in syncing from my Archlabs lappy to my RPi Nextcloud Snappy

The same system was working fine on my previous laptop

I have used cp -pr to copy the files via cable to the external hard disk on my RPi from my lappy, then used sudo nextcloud.occ files:scan --path="PATH TO FILES" , permissions etc etc

In any case I have managed to diagnose that the Nexcloud in itself is working fine

Most of the folders on my laptop sync fine

But a few cause a crash of Nextcloud & thne of the RPi (sometimes client connection is lost and no web interface connection, but I can still SSH in, but sometimes the RPI crashes completely)

I am starting to identify which foldrs, but since I have over 200,000 items finding the files responsible is daunting so I am asking if there are any ‘usual suspects’

i.e.

What are the files / items that commonly cause sync or other problems for Nextcloud?

And / or where can I look to try to identify these files (which logs / which log entries, etc?

I have already identified some .htaccess files, that I have zipped and there are no more

I have unchecked 'sync hidden files and added .htaccess to the ignore list (boots and braces)

Could it be the size &/or number of items of the synced folders?

Hoping for some input / suggestions to help me focus my search

Thanks in advance!

Nextcloud version (eg, 20.0.5): 25.0.3
Operating system and version (eg, Ubuntu 20.04): ArchLabs (Arch based)