samsung – Messages for web not updating with new texts and statuses

I am trying to use Android Messages for web. I am able to connect to the phone using the QR code, but after the initial connection, I do not get new messages automatically or any notification – I have to reload the page to see them.

When I send the message, the “Sending…” status remains and is not updated to “Distributed” either.

I have tried in Firefox and Chromium. I am using Ubuntu. The computer and phone are on the same network, and I tried with the computer using a cable or WiFi. The phone is a Samsung Galaxy S9 and the app is allowed to run in background (no battery optimisation).

I have had the problem for quite some time now, I couldn’t say if it used to work in the past.