Google could have a bug with the URL inspection software in Google Search Console particular to web sites on HTTP/2. The software reveals a malformed response when it’s run on the HTTP/2 server.
The person who posted this on Reddit stated “I am curious if anybody else is seeing this…. Once I take a look at the Crawled Web page information in GSC it is exhibiting the HTTP Response as “Malformed response”. Once I run a dwell check it checks with HTTP/1.1 which is okay.”
Gary Illyes of Google responded “Yeah I am trying into this. sorry. That means to say that is probably a bug in SC.”
Here’s a display screen shot (click on to enlarge):
I requested Gary for an replace about this however there was not one to be given:
no
— Gary 鯨理/경리 Illyes (@methode) February 15, 2021
Discussion board dialogue at Reddit.