It’s hard to tell without having a good look under the microscope to see what is going on. Maybe some of the liquid got onto the logic board and fried some components. Or if nothing is fried from the liquid spill, it could also be that you have corrosion on the board and that some of the components don’t make a connection anymore because the pads are gone. I would suggest to take it to a specialty shop that does this kind of repairs to have them have a look at it.
But maybe the repair will be more expensive as a new logic board/phone, so in the end you should take that also into account.