Malfunctioning European DoH servers

What is your recent experience with the following 2 DoH servers?
I have bad experience with European DoH servers recently.
https://zero.dns0.eu
caused many dns,error lines in log recently:

DoH server connection error: Idle timeout - connecting

So I decided to try a quite new one:
https://noads.joindns4.eu/dns-query
but it caused even more frequent errors:

DoH server connection error: Idle timeout - receiving status

Does any of the above work for you currently?

Unfortunately, no.

I’d like to use the same joindns4.eu server, but it isn’t working. While looking into this, I googled the exact error message, and this post was the only result I found.

Using the sniffer tool, I can see communication in both directions to and from these servers, so I don’t get the Idle timeout error.

> tool/sniffer/quick port=443 ip-address=86.54.11.13,86.54.11.213

According to https://dnsspeedtest.online/ DNS0.EU is usually practically inaccessible (too long response times)

Meanwhile I realized that 86.54.11.13,86.54.11.213 uses HTTP/2 while ROS supports HTTP/1.1 only.

Here you can vote for my FEATURE REQUEST: HTTP/2 support into DoH

I also reported this problem to DNS4EU 5 days ago, no response yet.