just make sure you use big enough containe at least 10 gallon. Netpot you would be fine with a 10 inch I only use 6 inch don’t forget your roots will be in container so the larger the better 10 - 20 gallon personally I would go with the 20 gal
I ended up getting my last 3 qbs and heatsinks from Cobkits because HLG didn’t have heatsinks wish they could figure out how to keep stock on hand it very annoying they have great product but stock is always an issue
You said you unhooked the main leads how were they connected wagos or tinned ?
Being on floor shouldn’t matter.
Do you have meter to check if there is power coming out leads going to cobs?
I would double check all the wires going to cobs first and go from there all it takes is one wire being loose or not making good contact also double check that it is all + to -.