Previously I already checked that the language variables existed in the corresponding file and they are already included in the file en-GB.tpl_YOUR-TEMPLATE-NAME.ini

After reviewing the file again and comparing it with the native helix ultimate template, I found the problem.

In the template language file (line 439) there is a variable COM_FINDER_ADVANCED_TIPS. This variable in the native file of the helix ultimate template has the text of its contents on a single line which is correct. In the template file, you have put it in several lines and that is what is generating the language error.

Helix ultimate ini file (correct)

Investa ini file (incorrect)

After correcting this variable, leaving it on a single line, everything has started to work correctly.