Intellij not showing submodules of multi module maven project

My pom.xml that has been stable for over 24 months is now not working within Intellij - and I can not figure out why it stopped doing so. Here is the modules section:

<modules>
    <module>tcpclient</module>
    <module>tfdma</module>
    <module>tf</module>
    <module>tfspark</module>
    <module>registry</module>
    <module>p2prdd</module>
</modules>

But now the already-existing Run Configurations are no longer working due to not finding classes. I can not even see the modules to try to fix the problem :note that only the Parent module is shown

Note that my next step will be to blow away all the Intellij artifacts such *.iml and .idea/* . But there is a cost to that: e.g. losing my (intricate) run configurations. This is not a preferred solution.

Any ideas why this would have happened?

Go to pom.xml of each module, right click -> add as maven project. This should solve the issue.

Version:2020.2.2