Previous versions of the client were installed at the user profile level (which caused problems for wapt deployment in a system account).
Since version 3.0.0 or 3.1.0, deployment to a system account has been working. I suspect the problem you're experiencing is related to a previous version installed under a user account. And indeed, I had forgotten that the software doesn't appear in appwiz.cpl (this could be fixed using wapt, but the client can only be uninstalled by the account that installed it, which is the system account in the case of wapt).
Before going any further, could someone experiencing this problem uninstall the client using the following command from the user account that installed it:
and reinstall it via Wapt using the system account, then test its functionalityMsiExec.exe /X{A74BDC23-D51E-4EB2-9175-F1EC67EC37F0} /q
The software is temperamental... if I understand your problem correctly, you need to start with a fresh install of the client!
