What exactly is the relation between Bisq and Bitcoin Core? What exactly is the relation between between Bisq and Bitcoin Core? It seems like Bisq can function perfectly well without Bitcoin Core, but if you do run Bitcoin Core at the same time, it appears to have issues (sometimes) with syncing the Bitcoin network. (Whatever that means in terms of Bisq, since it's clearly not a fullnode Bitcoin wallet.)
I've tried to figure, read and ask my away to the answer to this question for a long time now, but I've just been ignored.
In what technical/concrete ways does Bisq use/depend on Bitcoin Core, other than allowing you to easily click a button inside of Bisq to open up Bitcoin Core with the fields pre-filled in?
If it works without Bitcoin Core installed, is there some benefit in allowing Bisq to &quot;utilize&quot; Bitcoin Core?
As Bisq is not a full node wallet, it must connect to a full node in order to be able to receive transactions and learn when a transaction confirms. Without a local instance of Bitcoin Core, it will simply connect to a random node on the internet (there are some built in discovery methods for how it can find a node to connect to). If Bisq detects that you are running a node locally (i.e. you are running Bitcoin Core as well), it will instead connect to your local node and get its information from there.
Since Bisq relies on BIP 37 which Bitcoin Core has turned off by default since 0.19.0, you will need to enable this feature by adding peerbloomfilters=1 to your bitcoin.conf file. Otherwise Bisq will be unable to receive Bitcoin transactions. This is likely the syncing issues you are running into.
For some more information about local node settings in Bisq, you can read https://bisq.wiki/Connecting_to_your_own_Bitcoin_node.