Problems with the tunnel, until you ping some Yandex. Can you help?

Question

openvpn

Good afternoon. There is a company network. It runs a virtual machine with Debian 10 and an openvpn server. UDP. A five-digit port looks outward with forwarding to this machine.
An employee connects to openvpn. Ping to the terminal within the company's network through the tunnel jumps strongly. 50-100-400. It's difficult to work sometimes because of this.
But the paradox is that if you start pinging some Yandex (ping ya.ru -t) - the tunnel starts working well and the pings are very stable.
My question is this: is it definitely a provider? Maybe something in the operating system? Windows 10 user. Provider beeline. IPOE.

The tunnel translated to TCP, changed mtu, played with encryption.
In the openvpn logs at the moment when the pings start jumping - "Decrypt error bad packet id" (in red).

Answer 1

Try to switch to tcp

Answer 2

Put in an open-vpne keepalive shorter on both sides. UDP sessions can close quickly when there is no data transfer.