AUCTeX's LaTeX-mode is not recognized as a Latex mode

[lima-limon-inc]

Thank you for the bug report

• [X] I am using the latest version of lsp-mode related packages.
• [X] I checked FAQ and Troubleshooting sections
• [ ] You may also try reproduce the issue using clean environment using the following command: M-x lsp-start-plain

Bug description

AUCTeX's LaTeX-mode is not recognized as a Latex mode; and thus fails to launch the lsp server.

The following error message is then shown:

Warning (lsp-mode): Unable to calculate the languageId for buffer ‘informe.tex’. Take a look at ‘lsp-language-id-configuration’. The ‘major-mode’ is LaTeX-mode

Steps to reproduce

Open any .tex file with AUCTex

Expected behavior

The LSP server (in my case, texlab) should launch normally

Which Language Server did you use?

texlab

OS

Linux

Error callstack

No response

Anything else?

No response