Rebuilt transmission, the transmission fluid level low at hot

I had my car's THM440-T4 transmission rebuilt last year I would say 6 months ago. It has 800 miles put on it. I went today to check all my fluid levels and noticed at engine temperature the transmission level is low. It’s not lining with all the dots on the dipstick like the manufacturer says. The ground is bone dry with no leaks. At acceleration I notice a slight slip like as soon as you push down on the gas to accelerate at a green light. It’s not completely rough. Just a slight hesitate.

Would it be okay if I top it off when hot? I was going to fill about a half a quart. I don’t want to risk driving it for a long time without the proper fill level. I do know transmissions in general do get low from condensation and have to be topped off once in a while. So that’s why I am asking what to do.