My interpretation of what the OP’s situation, that they are adjusting noise-reduction and sharpening to their liking in LR, the using Edit In PS (not Exporting despite using that word) into PS and what they see in PS is much nosier than what they saw in LR and are wondering why things look different between LR and PS.
My guess as to the problem is that they’re adjusting LR-Detail settings (Sharpness and NR) using Fit zoom instead of 1:1 zoom and then viewing the image in PS, perhaps at 1:1 zoom or even at Fit-to-Window zoom in PS, and that LR’s resampling and PS’s resampling of the image for fitting to the screen are a bit different and PS’s looks rougher.
Unless the OP is comparing LR and PS at 1:1 or 100% zoom, differences are to be expected.