Neotrellis Grid - not being detected by serialoscd on arch linux, serialosc-device complains about missing .so file

serialoscd does not detect my grid on arch linux. My grid presents itself on the serial port /dev/ttyACM0, and if I start serialoscd it hangs, and doesn’t seem to detect the device (I tested this on a friend’s windows machine and the grid is properly detected). If I have another serial device connected (my USB->RS232 adapter cable, which is /dev/USB0) serialoscd attempts to connect to it and fails, so I have to keep that disconnected. If I run serialosc-detector, my grid is not detected by that either.
When I try to connect to the grid with serialosc-device /dev/ttyACM0 it complains:

couldn't load monome protocol module.  dlopen said: 
	/home/nico/.cache/yay/libmonome-git/pkg/libmonome-git/usr/lib/monome/protocol_mext.so: cannot open shared object file: No such file or directory

How can I get this working? (I’m pretty sure dlopen shouldn’t be searching for libraries in the package manager cache, and serialoscd detection would be nice)
I installed both serialosc-git and libmonome-git from the AUR packages. My grid is a neotrellis grid (rather than an original monome) but it is detected fine by serialosc on windows, so I’ve diagnosed this as a serialosc issue.

I’m not certain but this seems like something went wrong in serialosc build/installation? All of this behavior seems potentially attributable to missing protocol DLL(s). I’m using a monome grid c. 2018, but here is the install procedure I used.

% git clone https://aur.archlinux.org/libmonome-git.git
% cd libmonome-git
% makepkg -si
% cd ..
% git clone https://aur.archlinux.org/serialosc-git.git
% cd serialosc-git
% makepkg -si
% cd ..

This results in /usr/lib/monome/protocol_mext.so and other object files for the other protocols used by older grids, and I can connect with serialoscd or serialosc-device /dev/ttyUSB0.

I’m not familiar with how yay works or if that’s relevant.

ah, it connects for me if I do this. Somehow yay seems to mess up serialosc. Weird.
Unfortunately this doesn’t fix everything - Serialosc says it’s connected but no other software seems to be able to communicate with it. Any monome software I try doesn’t seem to work or reports I have no devices connected, the only thing I’m able to do is oscsend "127.0.0.1" 18335 /sys/info i 9999 and that successfully returns the serialosc system info, I can’t make anything else work.