Do you have a dryer in the Basement ?

Seysonn

A clothes dryer? Yes, along with a gas furnace.

Gas furnace is not a problem. Or should not be.

But I am just speculating the chemical odor coming out of dryer, mainly from things like fabric softener, static guard, wrinkle resistance stuff. Again, I am talking about a suspect.Tomatoes are freakish :-)

Seysonn

I wonder about the potting mix. Was it potting mix (suitable for containers?) I mistakenly bought a massive bag of organic Miracle Grow once, and when I was able to turn the bag over (after filling my containers), I noticed that it said (on the back of the bag) NOT for containers. Assuming that perhaps the reason was because of odours, I did nothing, and my plants didn't do well.

Back to your problem. Does the mix contain Coir? I have read that sometimes that can be bad.

In addition, we have to be careful or aged manure these days because some farmers feed their cattle hay that has been treated with herbicides. It goes right through the cattle, but persists in the manure, and tomatoes are very sensitive to such things.

I wish you good luck.
Linda

These were the small bags (easier to handle indoors) and definitely potting mix. I'll check on coir but MG usually uses peat.

The latter is what I think happened since it was an organic mix. Contaminated manure got into the mix. Since the repotting is really what these have in common.

I don't think it would be anything from the dryer. We don't use fabric softener or dryer sheets. And I have four bush bean seedlings that I repotted... two from a different bag. It's also showing distortion on new growth, the other two are happily chugging along with no issue.

I don't have proof for certain but the potting soil seems to be the common denominator.