You must have noticed at least to some degree how Bisq1 connectivity has degraded lately, and you probably know this is about Tor being under DDoS attack since a few weeks ago: Performance – Tor Metrics
If you also use Bisq2, you might have noticed that the situation is not as bad there.
The difference lies, among other things, in the additional data traffic that Bisq1 has, namely bitcoin nodes connections, and seednodes connections, and while the latter is less degraded, some users are reporting they cannot reach the minimum of 4 btc nodes connections to be able to start a trade, or complete open trades, or resync the SPV wallet.
This could be solved by refreshing tor files, which you can do manually if you cannot access the UI, or by disabling tor for bitcoin network connection, from Settings > Network, but that would be a privacy issue.
The best practice to follow, though, which is also in line with being a “true bitcoiner”, is to run your own bitcoin node and have Bisq connect to it.
SPV resyncs will almost become a thing of the past, and Bisq startup times will benefit.