Photos that export just fine in LR 2015 export very badly in LR Classic 10 under the same settings

[khristopher5CE1]

Hi guys so I'm having a problem with lightroom classic (10.1.1 but has been an issue in previous versions) where I'll export an image and it will come out with all the weird stuff you can see on the side in the first image but if I release the exact same photo with the exact same edit with the exact same export settings from lightroom cc 2015 it will come out fine which you can see in the 2nd image.

I've been using lightroom for years and I never had this problem until I updated catalogs and used them in classic. The last resort is to go back to using just cc 2015 but I've been doing a lot of stuff in classic which means I'll have to do a lot of resorting which would be a pain, and there'd probably be other issues so I'd rather avoid that

export settings were the same for both images

I have already turned off the graphics processor under preferences

whilst the grain shows up when I go to 1:1 in LRC 10, the problem is that this grain doesn't exist when I export in LR 2015 and never before did I have to go to 1:1 to see something that makes such a massive difference to my photos. 

I tried exporting under earlier processes in LRC 10 (version 3 & 4) which does help to a degree, but it doesn't work for every photo.

[Tony_See]

Are you exporting to each of your attached jpeg files from the same file format? 

What is that format?

Have you changed tour OS?

Cut back your jpeg compression to 80% can you and report if there is any improvement.

I think you might be seeing some sort of artifact, but not sure why yet.

[khristopher5CE1]

both the jpegs are coming from the same raw if that's what you mean (sony arw).

whilst I have recently upgraded from high sierra to catalina, I was having this problem with high sierra anyway.

I've tried cutting back compression and it doesn't solve anything