System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.71

Blender Version
Broken: version: 2.91.2, branch: master, commit date: 2021-01-19 16:15, hash: rB5be9ef417703
Worked: (newest version of Blender that worked as expected) - ?

Short description of error
[Please fill out a short description of the error here]
Two Objects, trying to transfer both UV maps from one object to the other.
Transferring the asymmetric labelled one worked. When the second one was added, however, it gave back this error message:

Both meshes have the same amount of faces/verticies/edges, same topology, are at the same position.
The desired UV-Map that I wanted to transfer was selected for the camera/render option on both meshes before pressing the "Transfer UV Maps" button.

Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]

Maybe - but only my theory - try using two UV maps on two objects. Add one UV Map slot on the target object, transfer it, then create a new slot on the target, rename it, select the UV Map holder object and try to transfer that as well. If it then throws the same error, we know what's going on.
My file is too large to upload.
If this has been fixed already or it was my fault and there is a way to achieve the transfer of both UV maps without overwriting one of them in the target object, please let me know, as well.
I might reply with delay, the issue is urgent for me to be fixed, though.