Fast n Vast Autoflower - Bizzare problem, help figure out?

Hello, ive been growing heavyweight's fast n vast, in light mix with perlite, 86w lights.

My plan was keep it 2 weeks inside under the 86w, then move it outside.
And all was going well, it was actually growing pretty big the first 2 weeks, but when i put it out it started damping off- i think.

The stem on the base got brown and half it's size. Fortunately it wasn't killed, it didnt fall over, so i took it back inside.

Since then it's been growing slower, but it HAS been growing, EXCEPT theres no new stretching.
So a couple new sets of leaves are literally pushing on each other.

I dont know how much a problem that is, or what i could do. Obviously the starting to damp off fucked it up, but when i took it inside it didnt continue, the stem was just smaller. And it DID keep growing new leaves, just no spacing upwards.

I never had something like that happen till now so i didnt know what to expect from the beginning. is the stem supposed to bounce back from damping off and get healthy width again? What about the no more stretching, something i can do?

Anyone that maybe has had that happened i'd appreciate any info. Thanks!

Difficult.

I think its pretty simple. Sets of leaves keep growing with no upwards stretching.

Not sure how well you can so with dampening off. Normally it's a killer even if you try various methods to save your plant. Best is prevention, control humidity and temps and you can prevent it.

Since it's an auto, you can't clone her. But if she's not then I'd salvage for clones and restart. Now the best thing you can do is give all the love and care that you can give and hope for all the best.