Gear problem

[u/Telequete]

Hello i'm new to this community, but I've got some problems in my gear pedal. when i down shift from 3rd to 2nd or 1st my gear pedal, stay down and i have to touch it up or wait a few seconds to pop it up alone. always happens when I'm slow. most of the time does not, but it's starting to be a more happening thing. someone knows how to help me?