It is set in a pvp team, a pve team, an event team, etc. You can go through all areas of the game and make sure it's not in any of your teams. This becomes especially fun when you have 3+ teams for all modes, so you may have a lot to sift through to find it. You might be able to expedite the process by deleting all your saved teams except for your main one from the default squad management screen. Not sure if that will work, however. I remember having your same problem and eventually finding it in my 3rd saved team for an Event. It can be frustrating.
do you know how to remove the "In Battle" tag on mech ? i cannot disassemble some mech with "in battle" tag
It is set in a pvp team, a pve team, an event team, etc. You can go through all areas of the game and make sure it's not in any of your teams. This becomes especially fun when you have 3+ teams for all modes, so you may have a lot to sift through to find it. You might be able to expedite the process by deleting all your saved teams except for your main one from the default squad management screen. Not sure if that will work, however. I remember having your same problem and eventually finding it in my 3rd saved team for an Event. It can be frustrating.