Looks like it could be WAY Interglobal (bought by Furrion in '22). Here's a full panel on etrailer that has round head+wand but shower mount looks identical to Lineage photos:
If they just capped off the fixed head then might be possible to just pick an aftermarket shower head.
RVs of America Off Road is using a very similar shower panel if not identical. About 10:16 into the first video on this page provides a glimpse of the shower panel.
You also have the option of contacting GD or going to their website, if you're registered you can search parts for those models. I think to order you have to call it in, not 100
% sure on that though.