Portal shows up as the normal, non BP portal but doesn't work, it says
Couldn't find TF portal at PooledMutableBlockPos{x=-175, y=55, z=588} even though it was just created?

logs.zip
I've gotten a similar error, uploaded it for you.

Are there non-grass blocks in your portal frame? It looks like TF will form a portal with a dirt frame whereas BP currently requires grass.

Please attach the full server log file.

I am pretty sure there was dirt, yeah