Tips suggested by the card reader

I tip generously. Usually ~20%, rounded up. At times more; less only for not good service. On the way home from bell choir tonight i stopped for a late dinner. The restaurant has a special after 8pm of $25 for a bottle of wine and a board of 4 bruschettas; normal price for the board is $16, and the wine varies, but is typical restaurant upcharge. When I paid, the card reader 20% generated tip was over $11! Apparently, it did not take the special into account.

Is it normal to tip on full price vs specials like this? I will say that there are some specials (free meals on veteran’s day, for example) where i do tip on the regular price (and i tip about 25%), but that seems different from a regular special. For example, would you tip on full price for happy hour pricing?

i stopped going out to eat because the back of house machinations and covid tipping math got too
much to deal with. " i go. i enjoy. i pay." it seems like a demonic maypole and kabuki economics had a
beautiful love child, and forgot about the diner and THEIR experience. like the famous character travis
mcgee said long ago, ‘no one is looking over your shoulder, no one is grading your paper, baby.’ trust yourself. if u let it slide, so be it, if you say, ‘not today’, so be it. be good with your choices and decisions.
ultimately, you are the adult in the room.