Multiple upstream set on load balance but favors only 1 after a few days.

[hnry]

I have 4 upstreams (https for 2x cloudflare, quad9, google) set to load-balancing. My bootstrap servers are a mix of cloudflare, google, level3.
If I hit test upstreams (passes) -> apply. It'll start working as I expect. But after a few days it's exclusively google. It's usually google.

Anyone know what's going on?

My only clue is the processing time is usually higher to cloudflare and quad9. But not sure why either, I get great pings to them. Regardless it shouldn't favor to the point of 15k requests to google, 1 to cloudflare, 0 quad9 & other cloudflare.

[hnry]

I hit apply / test upstream. And sure enough it's working again, but after a few days it'll just look like the OP pic.
Not sure why Google requests went down 15288 -> 15042...

[hnry]

See #3521 , #4751

And https://github.com/AdguardTeam/dnsproxy/blob/v0.57.2/proxy/exchange.go