Installed a floating click lock oak floor the other day and right after installation notice a slight depression when stepping on the wood floor. I thought I had the slab perfectly level, but apparently I did not. Of the 300sqft I installed only this small area it flexes downward about 2/16-3/16. Everything else is perfect. This area a couch will be covering so no traffic will ever go across this depression. Should I disassemble and redo it, or is 2/16-3/16 not that big a deal?

not a big deal....

Could have got a bowed peice in there, that will do the same thing. I would put the couch on it and move on.

Do you consider ~1 sq ft a small area?

Yes, 1 sf is small. If it bugs you pull it up and slip some cardboard under it.