@TP-Link Thanks for the reply. The downgrade indeed fix the vpn connection issue. We're running openVPN with custom profile. From the client side there were no obvious errors. The connection...

@TP-Link Forgot to mention that I connected to the modem directly and the same vpn was functioning without problem.

@TP-Link Thanks for the replay. I think I was on 1.51 previously. The connection issue started happening right after the firmware update, and no one else from my company is having issue with the vpn.

After update to 1.5.6 Build 20211018 Rel.35617 my openvpn to the company network stop working. Where can I find the previous version of firmware to downgrade? Thanks.

Similar case here. The wireless connection speed drops overtime and will bounce back after reboot the main unit.