There were 2 recent regressions in hotrod performance, one between commits dd5501c5e and 628819461 and the second one between 628819461 and db0890270. I didn't look for the exact commits, so the name of the issue might not be 100% exact...
It is easily reproducable locally with a single server instance, reproducer attached.

The numbers on my machine:

The JFR recordings (attached, captured is only the part of the test with gets) for db0890270 show a lot of time is spent in HotRodDecoder#resetNow(), and also the allocation rate goes from 100MB/s for dd5501c5e to over 1GB/s for db0890270. There are no glaring differences between dd5501c5e and 628819461.