Yes, this paper claims a weak relation between earthquakes and tides in some cases, but not enough to be of any use in prediction.

There must be a correlation at some level, since the tides cause stress and earthquakes are the response to stress, but the point is the rate variation due to the tides are at best a few per cent.

So this link (which I gave you on another board)
is not encouraging for earthquake prediction from the tides.

John