It sounds like large temp swings, when juicy tomatoes don't ripen properly ... especially on cold nights followed by warm days. The secret is uniform temp...

Celebrity was bred in part to address this problem. It is pretty fim a tomato but not as bad as they say :-) Look for an heirloom with similar characteristics if you want one but keep in mind many hybrids that are heat tolerant have this bred into them so will likely handle the fluctuations better. Costoluto Fiorentino, Pruden's Purple, Stupice maybe. I'm going to try Bradley next year, and it is probably a good bet for you too.

Happy Thanksgiving
PC

I grew Pozzano F1 from Johnnies two years in a row and it performs ok, but they are indeterminate, so by mid June they are pushing through the plastic of the tunnel.

I also grew Burpee Super Sauce and was really impressed with the outcome. Big giant baseball sized sauce tomatoes that performed well in the tunnel even with the crazy temperature swings. They performed so well that I'm debating on dropping the Pozzano all together and just grow these.