Description:
Whilst it is possible to use LanguageTool Premium with a plus email address, e.g., username+languagetool@domain.name, LibreOffice will not work with this.

Setting up LibreOffice for a premium account works, but automatic checking doesn't work, i.e., no spelling or grammar checking is performed.

Replacing the plus address with a standard one resolves the issue. Nonetheless, LibreOffice should wotk with plus addresses, as defined in the RFC 5233 Sieve: Subaddress Extension.

Steps to Reproduce:
1.Enter LanguageTool Premium credentials as described here: https://languagetool.org/insights/post/product-libreoffice/
2. Disable all other writing aids.
3.Load a test document, or simply type, and no autocorrect suggestions are displayed.
4.Change LanguageTool account to a non-plus address, restart LibreOffice Writer, and retest. A

Actual Results:
No highlighting for spelling and grammar.

Expected Results:
Spelling and grammar errors should be underlined.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
Version: 7.6.3.2 (X86_64) / LibreOffice Community
Build ID: 4fe86607b5ac922e55f140471fda9b60bdaa980d
CPU threads: 16; OS: Linux 6.5; UI render: default; VCL: gtk3
Locale: en-GB (en_GB.UTF-8); UI: en-GB
Calc: threaded

LanguageTool support contacted to check the API.