Fleet Manager Creating single craft fleets

Just wondering if this is happening for anyone else. I use fleet manager to manage all my fleets. I use it to create them and to reinforce them. Occasionally when I reinforce I end up with a new Fleet that contains one ship. Its never been much of a problem. Usually only creates one or two of these and I'd merge them or use them as the jump point for the next Fleet.

In my current run however it created 10 to 20 of these fleets every time I hit reinforce. It started happening in the late game when I'd have 100 to 200 ships to replace across my fleets. It's causing issues as my fleets aren't being reinforced and I'm at war with an FE.

I'm not running any mods.