quibbler
/ˈkwɪb.lər/Definitions
1. noun
A person who habitually finds fault or raises trivial objections; a petty objector.
“He’s a notorious quibbler who always tries to find loopholes in the argument.”
2. verb
to find fault or raise trivial objections in a petty or annoying way.
“Stop quibbling over the details and focus on the big picture.”