12.2.01 Adding Node Fails w/ Verifying '/tmp/' ...FAILED

I am trying to add a node to our 2-node RAC cluster running RHEL 6.8 and Oracle 12.2.0.1. The new node is running RHEL 7.6. This should not be an issue as I have an internal RAC cluster where one node is on 7.6 and the other on 6.8 (pending OS upgrade).

When I run cluvfy, ( cluvfy stage -post hwos -n 685921-db5,685925-db6,1103477-db7 -verbose ) I get the following error: Failures were encountered during execution of CVU verification request
"stage -post hwos".

Verifying '/tmp/' ...FAILED
1103477-db7: Version of exectask could not be retrieved from node
"1103477-db7"

I've checked the Oracle notes and adjusted the MTU size on the new node, created a dummy file on one of the current RAC nodes and successfully scp'd it over to /tmp as the grid user on the new node.

Googled the daylights out of this as well. No luck.

I'm thinking I'm missing a package or something, but the lib* rpms all seem to be at or above the requisite levels per Oracle documentation.

Can anyone suggest what might be a problem here?

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