I am trying to add a class module by right-clicking in the folder inside the code explorer and it's showing nothing.

Version 2.3.1.4431
OS: Microsoft Windows NT 10.0.17134.0, x64
Host Product: Microsoft Office x64
Host Version: 16.0.11126.20196
Host Executable: MSACCESS.EXE
This is not universal behavior. I'm on 4431 as well and not experiencing this issue.
Version 2.3.1.4431
OS: Microsoft Windows NT 6.1.7601 Service Pack 1, x64
Host Product: Microsoft Office 2010 x86
Host Version: 14.0.7224.5000
Host Executable: EXCEL.EXE
I must have spent an hour and a half right-clicking last night and was only able to replicate this once. It appears that something? is causing the bind on AddModuleCommands to either break or recycle in a way that causes the visibility of the commands to toggle off. We did identify some potential casting issues in the templates sub-menu that is addressed in #4718, but I can't definitively declare that as the cause.
Would it be possible to set your logging level to "trace" in the settings and post the log file if this happens again? I doubt there will be much relevant information logged (binding problems don't tend to show up there), but it would at least help rule out things like exceptions in the EvaluateCanExecute procedures.
I reverted back to version 2.3.1.4414 after I discovered this. I'll install the latest version and see if this is still there then comment back.
Everything is good now. I discovered another bug though. Will open another ticket with the log.
Most helpful comment
Everything is good now. I discovered another bug though. Will open another ticket with the log.