Look at the Boeing 737, it has like a hundred minor computer alerts that pilots see and ignore every month. Your boss knows the system better than you and if they say it's minor, it's probably been logged and will get fixed on the next maintenance cycle. Grounding a plane over a tiny, known glitch causes huge delays and costs the company a ton of money for no real safety gain. Honestly, you're paid to follow procedures, not second guess every little thing based on a gut feeling.
Man, I used to be super strict about reporting every single thing (like, zero tolerance). But Paul_Morgan's point about known glitches and procedures actually makes sense here. Now I get that always grounding a plane can cause more problems than it fixes.