My Ubuntu installation has started to act up - everything freezes every once in a while. With perhaps 15-20 second intervals, especially when scrolling a long page in a browser, nothing happens for 1-2 seconds, then it moves. Also clicking tabs in the browser, clicking links, alt-tab switching between windows, everything. However, not the mouse pointer - I can move that around, that doesn't freeze.
I have 16 GB RAM, only half of which is used at the moment. I have 2 GB swap, none is used right now. My eight cores are all below 20% right now.
I can usually solve the problem by rebooting, but it comes back. This is an old 22.04.4 LTS installation (a couple of years), and this hasn't been a problem before.
Any ideas?