Agree with another poster that gloves WITH padding can cause numbness. I have a pair with pads across the pads of my palm that give me numb hands after an hour. I don’t wear them much. Conversely, I like the specialized with pads filling the negative space in the middle of my palm. Part of their body geo line.
I also notice numbness with certain hand angles before a bike fit, particularly ends of the drops. Causes severe wrist/hand angles that I think contributes.
Lastly, and this is probably more special case, I have Raynaud’s, and particularly cold rides, or changes in temperatures (like a long descent after a long climb - even in warmer weather), totally numbs my hands, to the point that I have difficulty shifting.