mainstage midi bank select not working for switching patches

I like to switch patches from my Roland g-70 workstation using MIDI commands.

When sending program change numbers only, I can switch beetween patches configured for program changes only. That works fine (channel 13 used):

19:55:09.869 From UMC404HD 192k Program 13 1

When configuring a patch with the Bank Select option AND Program Change attributes checked, nothing happens if I send a bank select e.g. MSB 122 LSB 0 followed by a PC 28:

19:55:09.878 From UMC404HD 192k Control 13 Bank Select 122

19:55:09.879 From UMC404HD 192k Control 13 Bank Select (fine) 0

19:55:09.879 From UMC404HD 192k Program 13 28

Any idea what's my mistake?

Thanks, Guenni