MIDI Guitar 3 on Logic Pro - Error Message

I have a Mac (OS 12.0) running Logic (10.7.1). I set the buffer size to 128 and turn on low latency. The MIDI Guitar 2 plugin opens as expected, however I get an error message when opening MIDI Guitar 3:

Your DAW is running at an unsupported buffer size of 2048. Only 128 or 256 is supported in this BETA version. Set your DAW’s buffer size to 128.

Please advise, and thank you!

Logic will use these huge buffers when nothing is happening. The reason nothing is happening is likely that you didn’t enable input monitoring on the audio track where MG sits.