SSL/VPN handshake failure through RS300 confirmed router-side issue

I started having issues with connecting to my WFH on 9/6/2026. First it was my spouse that couldn’t log on to her work laptop device with a different client sign on. Mine was Omnissa Horizon Client I kept getting error: an SSL error has occurred, the server connection error followed. All other device on my home network works just fine. With download speed at 2247.17 while upload speed 296.68. Called my network provider all seems fine. I took the device to work it work brought it back home, use my mobile personal hotspot i was able to log on but whenever I am on the ethernet cable connected to my router I receive those errors. Then I connect directly to my CM300 modem port I was able to log on. Which brings me to why the sudden change on the router. What could be blocking my Horizon handshake. 

direct-to-modem works, RS300 in the path breaks SSL handshake. Now looking to purchase a new router