Libreoffice hangs on Mac (Big Sur) when accessing files on remote server over cloudflare tunnel


I’ve recently moved my remote access (working from home) setup from OpenVPN to a Cloudflare Tunnel using their WARP client on my home machine and running Cloudflared as a service on the OpenWRT based router at work to access the file server there. The connection uses the SAMBA protocol.

All of this is on a Macbook Pro running Big Sur 11.6.2. No plans to upgrade to a newer Mac OS for a while yet for reasons I won’t bore you with.

Overall I’m having much better reliability and speeds opening, working on and saving files directly from the file server with the Cloudflare tunnel than I was with OpenVPN, using a very wide array of applications (Graphic Design, an IDE, pdf readers, audio file players etc.), except when it comes to Libreoffice.

As soon as I connect to the remote server with the WARP client and try to do any kind of file access operation in Libreoffice, I get a significant number of hangs (beachballs) and it might take 1-3 minutes to open a small (eg. 50kb) writer document. Once it’s open, I can work in it fine, but saving mid-session takes another several minutes. Even closing the document at the end of the session can take 60 seconds.

In Activity Monitor, both the Libreoffice and processes show as ‘Not Responding’ and the number of hangs in each process begins to climb - a minumum of 4 or 5 each time, sometimes more than 10 for the Libreoffice process.

For what its worth, the latest release of Apache OpenOffice displays the exact same behaviour.

OnlyOffice by contrast is fine. It’s probably slightly slower at opening or saving a file on the remote server than it is on my local machine, but we’re only talking about a second or two. Our workplace is very invested in Libreoffice though so we’re not seriously considering implementing a change. Onlyoffice seems too limited anyway.

So I’m wondering if anyone has any tips for where to start trouble shooting this very specific problem combination of Libreoffice accessing files on a remote server over a Cloudflare tunnel?

I’ve tried starting LIbreoffice in safe mode and it didn’t make any difference.

Thanks for reading.