Language Client bug: QtCreator fails to start RLS after version 4.9.x

In QtCreator 4.9.2, I'm totally able to use RLS (and hence I don't upgrade). I just set the path of RLS in "Language Client", and set the file pattern to *.rs, and everything works fine. However, starting from version 4.10 (and now 4.11), RLS crashes all the time and never starts. QtCreator attempts to start it, but it keeps crashing. QtCreator keeps retrying every 5 seconds for a while, then gives up.

To reproduce, install rust, run the command:
 curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 Then to install rls, run the command:
 rustup component add rls rust-analysis rust-src
Start QtCreator and enable language client, then add a new entry for rust in language client in options and use the path of RLS, which is in /home/user/.cargo/bin/rls, and set the file pattern to "*.rs". Then see that whenever RLS it tries to start, it crashes.

I'm on Debian Buster, 10.2.

Given that it works on QtCreator 4.9.2, I don't believe it's a bug in RLS.