This happens in the plugin as well as the standalone Synth V Studio Pro. Tempo changes and sig changes seem like they’re occurring in the right place but the display is totally messed up and they show on the wrong bars. Pic attached. The bar of 3/4 is very evident in the picture. You can see from the bar lines that there are bars of 3/4 at bar 3 and bar 5 but the 3/4 and 4/4 markers are all bunched up in the first 1-2 bars.
EDIT:
As noted, this happens in STANDALONE Synth V Studio Pro 1.11.01b (as pictured). It also happens in the plugin which was VST in REAPER 7 without the additional ARA running (the ARA always seems to crash REAPER so I haven’t tried it yet, but that’s a different issue). I can reproduce this in STANDALONE Synth V Studio Pro, as pictured.