It sounds like you have loose debris (****, junk, dust ) in your fuel tank or float bowl maybe lodged in your jet even.
When you let it sit it settles when you ride it goes into suspension and clogs stuff up.
Drain your tank, clean your jet with a fine wire. Install a new fuel filter.
If this does not work, did you wash the bike or get rained on.
Moisture turning into steam and condensing on your electronics. will stop you after awhile too.
Both have happened to me.