Horrible quality when saving to .jpg

Hello- I'm not sure if this is the correct area. I use Creative Cloud and all my programs are up to date. Part of my workflow has been saving as a high quality .jpg from my .psd. Today the quality of the saved.jpg is horrible. Lots of grain almost as if I've increased the grain on purpose. I have checked in preferneces to see if something got 'changed' and everything seems fine. I use 'save a copy' because my 'save as' button does not have a .jpg option. I've tried Export both a quick export as .jpg and a regular export. Same results. I found that if I open the .psd in Lightroom I can export it and the results seem good! Since in Phtoshop any .psd file is flattened before saving so I don't believe the oder of the layers should have an effect.Does anyone have an idea of why this is happening? It's getting me upset, I would like to not have to switch apps just to make this work. I do all my editing in Camera Raw and Photoshop. BTW- I would have included files but my .psds are more than 47MB. I tried flattening a copy and then saving as .jpg but that did not work either. I'm flummoxed, it worked a few days back. I appreciate any help. I'm not a 'newby' and do know my way around Photoshop but this has me stummped.