Rhel services issue

I am trying to resolve an issue with a Rhel 6.9 system. The system is provided as a solution by a vendor in an isolated enclave, so the vendor has been providing application updates and rpm updates periodically. We host their software on our servers.

The system in question acts as the gateway, and is running on a Dell R310 server. The issue occurs after it has been running for about 4 hours. If I run the command

$ sudo service --status-all 

the command takes a few seconds to start, takes about 60 seconds to run, and about 45 seconds is spent displaying the iptables rules.

If I run the command

$ sudo service iptables status

the command takes a few seconds to start, and then immediately displays the iptables rules.

If I reboot the system and repeat the commands, they respond immediately. Something starts failing as it approaches 4 hours. Strangely, this issue first occured in June a year ago. The vendor came out and reinstalled the software. It worked fine until this June, when the issue started again. The vendor said they think it might be hardware related, but I'm not sure. I ran diagnostics when the issue happened last year, and it indicated no issues with the hardware. I don't like coincidences, and it seems strange to me that it happened in June this year and last.

I've tried comparing before and after sos reports, but there is so much data there it's hard to correlate the differences. I have never experienced this issue on a rhel system before. Does anyone have a suggestion on how to isolate the issue?