I’ve been running Nextcloud AIO on Proxmox for almost 3 years without stability issues, including daily work with files 10 GB+.
I’ve documented my large file sync tests here:
https://help.nextcloud.com/t/testing-large-file-synchronization-with-nextcloud-aio-and-nginx-proxy-june-2025-update/226681
And here is the complete deployment guide of my setup (Proxmox + Nginx Proxy Manager + Nextcloud AIO + Watchtower):
https://help.nextcloud.com/t/proxmox-nginx-nextcloud-aio-watchtower-deployment-guide/233643
If I can suggest one thing: avoid using Proxmox helper scripts for this type of installation. Stick to the official Nextcloud AIO documentation (which my guide follows) and you should not see VM crashes from large file uploads.