This seems to happen only at the start of a new round / map or when joining a server. Basically the merc that is currently active is not the one highlighted in the limbo menu. It’s not only misleading (you end up spawning with a different merc than the one you though was selected), but you can’t even use the limbo menu to pre-select the highlighted merc for your next respawn because the “apply” button is not available since the game thinks that merc is already you selected one.
In this specific case:
Menu was initially showing Fragger as selected, but I spawned as Phoenix (see hands and weapon at bottom of screen). Going back to the limbo menu, Fragger still showing as selected and cannot force in that selection since apply is unavailable.

