LR CC 10 export is overcooking colors

This started within the last week. I haven't changed any export settings. The green and red colors are now noticeably hotter/more saturated/more vibrant in the exported file as compared to what the image is in LR.

What has happened?

The colors hold true if I export a TIFF but the file size is 15x bigger.

It may be temperature thing.

But whatever, I have to dull the image a tad before export to JPG to have an exported JPG image that looks proper.

Have you always exported aRGB version JPG? I ask because for many many years, no commercial color print labs would print aRGB...they always converted aRGB to sRGB first! It was only within the past (estim.) 3-5 years that anyone on POTN could even NAME for me a vendor that printed aRGB files directly!

(I do not have direct experience with an aRGB converted to sRGB input print, to know how monitor vs. print comes out.)

My camera is set to aRGB, my monitor is calibrated to aRGB, I have always exported to JPG using aRGB. Nothing is ever printed, just stored and shared digitally.

This started in the last week or so. I caught it in a recent cardinal photo I posted. In the exported JPG image he is far too red but looks proper on screen in LR. So I started paying attention and this is happening consistently now.

What are you viewing the exported images in? Some programs (windows or otherwise) and browsers are not colour managed and will display them incorrectly.

Since aRGB is intentional and long standing, it would not explain 'recent change'.
How about the possiblity of using a new printer profile? Or a new monitor profile?

I'll jump in too, same has happened to me.
Use Adobe Lightroom Classic with an Eizo monitor, calibrated monthly.
After editing and exporting into sRGB (as most of it's website related), I started to notice the changes when looking at the images after saving them.
They came out overly saturated red and totally not what was edited on LR.
I ran myself bonkers trying to find out why, the only thing I can put it to is the windows (if you're on windows) is their picture viewer.
I saved the images to a USB and opened them on my Surface Pro and they looked fine-not sure why or how...

I have also tried to save them as a TIFF file, opening these on my computer was also a problem, flat, grey and colourless, again not how I edited them.

I would put it down to the picture viewer possibly. If you can see what they look like on another computer then try that.

As for saving file to web or just viewing, sRGB would be best.
Printing then go for aRGB.
Hopefully someone can answer the question as to why, I'm still not 100% sure.
All the best,
S

On a side note:

Based on this info provided by BenQ I am going to begin using Microsoft Edge over Chrome.