Elbow pain during tricep extension?

Just something I've noticed in my last few upper body workouts - a pain in my elbow during overhead tricep extensions. It only happens in my left arm - which is my dominant side!

Is this simply a case of needing to try a lighter weight, or could it be a sign of something else?

I've noticed it a few times now and it's not hugely painful, but I would like to figure out how to deal with it now before it gets worse! 💙