How to ensure tags are included when upgrading to Elements 2019?

I have installed the trial version for Elements 2019 and followed the steps where the programme asks to convert existing catalogue. I did that, but only the tags of one subfolder came across. None of my collections came across and none of the tags of the other subfolders and files.

I have looked in previous responses on this forum (it seems to be a common complaint over the years), but they were not helpful.

Last year I downloaded a free trial for 2018 when my catalogue was on the actual computer itself, that didn't work, and now that I have the catalogue on an external hard drive, it is still not working. In both cases only the tags of the same sub folder transferred.

Given I have a lot of subfolders, it is stopping me from upgrading to a newer version. My existing version is Elements 4.0. Is that version too old to transfer the tags from?

I hope someone can help, because I am not keen in going through my 50,000+ photographs again for a manual re-allocation of tags etc.

Many thanks in advance.

S