Glad you figured it out and got things to work in the end.
Another consideration ... while you changed your needle, did you change the type of needle?
Often times with batiks, you want/need a sharper type of needle than a conventional Universal. Perhaps with a different needle type, you could have avoided tension adjustments.
As you discovered, when doing practice work to check that all is working fine ... it's important to replicate it fully with the same fabric, batting and threads. Likewise, if the fabric has been pre-washed, starched etc. ensure the practice piece is the same in that way too.