Thought it is worth mentioning: using standalone Tomcat installation path solved the issue with inconsistent page load times i have mentioned here when 1st load took like 5-6 seconds and subseqent loads took 0,001 seconds
Solved the issue with non-unicode characters shown as “?” in most parts of the app as well.
Looks like Grails v3 with integrated Tomcat should be avoided in the current state 
Sorry for wasting your time on wild goose chase.
PS:
There was a bunch of warnings during startup similar to
[2024-11-23 15:16:12] [warning] Unable to add the resource at [/WEB-INF/classes/requisition/_requisitionItems2.gsp] to the cache for web application [/openboxes] because there was insufficient free space available after evicting expired cache entries - consider increasing the maximum size of the cache
Do they have to be addressed or can be ignored?