Seems strange and if that was it, it is definitely a bug. When you logoff, your ship will attempt to emergency warp out before being removed from space after any engagement timers have expired.
If your ship can’t warp, it just sits there. Should still be totally 100% lockable whether it emergency warps or not. Frustrating bug for it not to be.
If you look at the lossmail for STOP AND FRISK (linked above in the thread too):
The Mach is fit with both ship and cargo scanner. Doesn’t preclude using other alts to scan targets enroute in other systems, but the Mach looks perfectly capable of checking targets as well.