When version 8.6.0 was created it was (probably by mistake) based on version 8.2.1 instead of 8.5.0.
The result is that all versions on the 8.x.x branch from 8.6.0 and onwards don't contain the changes made to 8.4.0 and 8.5.0 (such as bumps to Kotlin and Ktor amongst others).
Conversely the "master" branch don't contain any of the fixes in 8.x.x.
There are a couple of solutions, but I leave it to the maintainers to decide on the best course.
One option is to merge all changes up to 8.5.0 into the 8.x.x. branch. Another one is to cherry pick.

When version 8.6.0 was created it was (probably by mistake) based on version 8.2.1 instead of 8.5.0.
The result is that all versions on the 8.x.x branch from 8.6.0 and onwards don't contain the changes made to 8.4.0 and 8.5.0 (such as bumps to Kotlin and Ktor amongst others).
Conversely the "master" branch don't contain any of the fixes in 8.x.x.
There are a couple of solutions, but I leave it to the maintainers to decide on the best course.
One option is to merge all changes up to 8.5.0 into the 8.x.x. branch. Another one is to cherry pick.