`f` followed by capitalized link hint letters doesn't open new tab

Describe the bug

f command followed by capitalized letters as link hint is supposed to open the link in new tab. It behaves correctly on Vimium 2.1.2 in Firefox 116.0.3 under Linux.

Now I switched to LibreWolf 116.0.2, I installed the same Vimium 2.1.2 from Firefox extension catalog. I backed up the Vimium configuration from Firefox and restored in LibreWolf. But in LibreWolf, f command behaves differently. After f command, capitalized link hint letter opens in the same tab, just as small letters. I couldn't find a option for this behavior.

How can I get more insight of this issue? How can I see some logs?

To Reproduce

Steps to reproduce the behavior:

1. Open any website with link in LibreWolf.
2. Press f to follow link hints.
3. Type a link hint with capital letters.

Expected behavior:

Link is opened in a new tab.

Actual behavior:

Link is opened in the same tab.

Browser and Vimium version

LibreWolf 116.0.2 and Vimium 2.1.2.

No source files or tests are named. First reproduce the issue in LibreWolf 116.0.2 with Vimium 2.1.2, then compare the same f command and capitalized link hint in Firefox; inspect available logs while following the reproduction steps. Done means capitalized hints open links in a new tab without changing the expected behavior for lowercase hints.