MIdi Guitar 2.2.1 component plugin problem in garageband

Hi Ihad a problem like the one shown in the picture, about midi guitar plugin.
On my computer I am running Mac Catalina 10.15.4, midi guitar driver MIDI-Guitar-2-for-MacOS-10.15-and-later, I have an UAD Apollo Twin Quad Thunderbolt with the last driver UAD-Mac-v9111. The message is pretty clear but impossible for me set a buffer in the the host (garageband) as specified. Keep in count that running the stand alone midi guitar app everything run without problem in the same environment. Do you have some suggestion?

as soon as your record enable the track, the buffersize should go to 256.
I’ve experienced that sometimes you need to start to record once, then Garageband initialises MG. The rest of the session MG will be kept alive then.
Garageband is very trimmed down in functionality, so handling sometimes is a bit cumbersome.