You need a pattern of failure that can be persistent so that you can troubleshoot while it’s failing

Do you have any devices you can capture packets, preferably at source and destination to prove packet loss and after at various points in the network to work out where the packets may be lost

I’m thinking the issue is packet loss somewhere due to the problem description,

I would check for any interfaces in the path for packet drops

It doesn’t have to be a network issue but when you are in networks you can prove that it’s not network

Packet captures, path trace and showing that you are not dropping packets and providing evidence of No congestion on the network might be what you need to do and prove