Vertex group fix (not working since >2.81)

Every time I click somewhere in object mode, all the vertex groups disappear at once.

This post is the only one I found adressing this issue: blenderartists.org/t/vertex-groups-disappearing-in-2-93-4/1330980/7

Could it be linked to a parameter in the user preferences that would automatically be used on newly downloaded versions?

Without it, there is no animation with armatures possible...