Issue with non-transparent proxy

Recently (may be related to Windows 10 2004 update) I have had a very strange issue. Generally it seems to effect when connected via WiFi but it has also occurred on hardwired as well.

Both my WiFi and hardwired are on the green interface which forces non-transparent proxy and I also have a blue interface which is configured for transparent proxy. My WiFi has two SSID’s one that connects to the green network and one to the blue.

The issue that I am seeing is that when connecting to the green my WiFi connection will on occasion drop and then reconnect and at times although it will pass traffic the network notification icon will show that I am offline.If I switch to the blue network SSID this does not occur.

My WiFi AP is broadcasting both SSID’s as the green and blue network’s are on different VLANS and it is an enterprise class AP (Aruba) so it is not likely an issue there.

My reason for the two networks, blue and green, is that general access requires an authenticated proxy and certain things i.e. IoT, use the blue network as they don’t work well (or at all) with an authenticated proxy.

My proxy settings are distributed via PAC file which has not changed in a number of years and that would only really effect applications that read it such as browsers. I have also set the winhhtp proxy in netsh to direct traffic to my ipfire box so for non browser applications they would be using that.

I do not see anything of particular interest in the squid logs as well

Any ideas ?

Where is the connection to the proxy here? It looks like you simply have an issue with that AP to me.