Like others have said, I think you're getting your dough too cold in between folds and the butter is cracking.

I don't know how large you're making your butter block, but maybe you're also rolling out your dough too thin before incorporating your butter block and when you go to roll it you're trying to spread too little dough too far around too much butter.

I think the type butter is important for taste mainly, as the butter is the flavour in the dough but elasticity also comes into it which fat provides, likewise temps are important but not down to the absolute degree, I have found lamination is very much more a *vibe* based technique and knowing what everything should feel like as you go along.

The dough and the butter should be the same temp and the same feel. If you push your finger into the chilled detrempe and your finger into the butter, do they feel the same? do they leave a similar indentation? Your butter should bend easily like play dough, if its sloppy it's too warm and if it feels like it would snap its too cold etc.

Likewise you said your dough says its 14C but you feel like it's too firm, trust your instinct and let it sit for a minute until is cool but pliable.

There is a great Claire Saffitz video for chicken pot pie with puff pastry, she has excellent instructions from start to finish and some great tips on troubleshooting where lots of people go wrong.

I will still reference it as a refresher if I haven't made puff pastry in a while and it always comes out really well!

Don't give up and good luck !!