You never want to use any type of lube on the game. It will just get gummed up and screw things up later.
Just to clarify, is it the flipper button that is sticking or does the button release?
Assuming it’s not the button, the first thing to do is see if it’s or mechanical or electrical. Play the game and when it happens, immediately turn off the game. If it says up, something is binding mechanically. If it drops, it’s electrical. I suspect it will stay up since you said lube helped.
Do you know how to open the game, remove the balls and raise the play field?
EDIT -> You might want to post your location. Pinball people are EXTREMELY helpful. You’d be really surprised at who will stop by and show you how to work on your own game. I’ve done it for people and I’ve had people do it for me. I’ve made quite a few friends that way.