VPN Not Working with SB8200

My SB8200 modem appears to be no longer allowing me to access my work VPN.  The internet works otherwise.  I originally thought this was an issue with my work computer; but, on troubleshooting with my work IT, we determined that wasn’t the issue (I was even given a new computer, which did not resolve the problem).  I then thought it might be an internet provider issue; but, on contacting my internet provider (RCN), they rebooted my connection among other potential correctives, and determined the issue wasn’t coming from their end.  Both my work IT and internet provider suggested this was likely a modem issue.

Additional context:  I haven’t done anything to my modem (I have not touched it) before the issue arose.  I restarted my modem after the issue arose; that did not correct the issue.  This issue just started one morning and has been going on for two weeks now.  I am able to log into my VPN through other internet sources not linked to my modem (e.g., phone hotspot).  Please help!