I wasn't aware of a new GZDoom release. Normally it shouldn't mess with sbarinfo stuff like this. I cannot see anything significant in the changelog that would explain a change of code behavior. I noticed that the texture system got a revamp in 3.7.0, though. Since the split statusbar completely relies on a textures lump, it would probably break if significant changes to declarations etc were applied. However I find that hard to believe since developers usually try hard to maintain compatibility to older mods with deprecated code.
In your screenshot you can clearly see that the bar is cut in completely different places and assets like the mugshot background (black square) are placed incorrectly. This indicates that positions defined in textures lump are not properly interpreted. I assume the normal (non-split) version works properly?
I cannot test this by myself before next week, but I am strongly tending towards this being a problem with GZDoom. If stuff doesn't work any more the way it did before, that's usually the case.
Unless you are loading other mods affecting the statusbar, of course. Be sure to check your launcher settings (if you are using any) and autoload sections in your gzdoom.ini file.