You might have an issue with the attached underlayment and the XPS board. The two, when touching, might cause a very annoying squeaking. You will probably want to lay down some plywood over the XPS so that the two don't touch.

Traditionally WOODEN substrates are not allowed vapour barriers. Concrete normally requires it. Your screen shot does not say whether or not it is discussing plywood or concrete. And it doesn't mention if it is above, at or below grade.

Sorry I meant I have the XPS boards on the walls for insulation to protect against water that comes through.

For extra protection, do you recommend that I lay down the 6mil barrier over the concrete floor and then install the lifeproof LVP?

Best practices has a vapour barrier used over top of 'below grade' concrete slabs. I am unable to read the entire installation instructions which means I cannot help beyond what I've already stated.

Ok great. Yes i couldn’t find much specific guidance in the instructions. But I guess it doesn’t hurt to use the vapor barrier. Thanks SJ