I see a couple of possibilities but given the off-color in the photo I can't be sure. There are some small white spots that look like stem edema caused by overwatering.

The larger greenish-brown patches "could be" Early Blight but they are usually more brown and there don't appear to be any signs of it on the leaves that I can see and it usually shows up there first. So they "could be" just more but older edematous patches.

So if it was my plant I would cut back substantially on the water. If it is all due to rain then drain out the reservoir and pull back the plastic so the soil can dry out and continue to monitor the plant. I would also begin a fungicide spraying program in case of EB.

Hope this helps.

Dave

Unable to see sufficient detail to say for certain.

A possibility for the "white spots" -- if small & bulging out of stem, might be root initials. Common in humid conditions.

I took another pic and added some text and arrows to make it clearer what I was referring to. Maybe its normal or maybe not- just making sure- I did see some moisture trapped under the clear trashbag cover- Ill post that pic too

I had the same thing happen to one of my two larger plants that I had in a nursery pot waiting to transfer to the ground. It had been outside for a couple of weeks. The first day we go a sustained breeze with some fairly significant gusts, the same 'blisters' appeared. I think it was wind damage. I thought I had given it enough wind protection that day but apparently not. My leaves were a little droopy as well. I brought it back in once I saw it in this state.

It seems to be doing fine now...except for the stem marks.