The difference is that the Acer m3 works with Simo an eSIM platform, but the Connect M3 does not.

These are the same devices (Manufacturer Ref. FF.G1QTA.001 and FF.G2DTA.001) which should both be called Acer Connect ENDURO M3 5G Mobile Wi-Fi".
However, the FF.G2DTA.001 version comes with 20GB of international data.