If mass-answering is your issue, then many satisfied users would not have been benefited here. It is not very often that anyone answers posts in the forum lately after the start of the Ukraine war. I am doing my best to keep the project alive. Checking for code updates and code commits will reveal that clearly.
Thanks to this post, I have added this solution to the wiki at the end of:
https://frontaccounting.com/fawiki/index.php?n=Main.OpeningBalances
In case my suggestions have sent you on tangents please note that all this is part of checking the possibilities as I thought might expose issues with PHP versions. The Job offers section is there for professional assistance in case the general community does not elicit a solution.
Adding a new user post was meant for another post.