LR Classic transfer to Mac Mail soft/out of focus when I send it as a "Large " not the actual file

LR Classic transfer to Mac Email out of focus when I am sending an Image via e-mail.
When I send an image to Mac Mail to send out, I now notice that the "Large " in image Size is slightly out of forcus or soft compared to when I use the Image Size as actual which is a high MB
The jPeg Size of actual is 11.8 and the jPeg Large is 586kb as an example.
I have had LR for 5-6- years and Photo Elements Prior and did not notice a shift if focus quality.
I checked all my settings  and they are the same:
Quality 100 and Resolution 300 pixels per inch
I say that it is slightly out of focus or perhaps it is soft, I am not an expert of the differnace.
When it first opens it quickly snaps from good focus to out of focus/soft.
Any deas, I find it hard to believe that I would never have noticed this, obviously there is no way to tell.
I also checked older pictures and they do the same snap quality out of Focus/soft.

I believe I posted this in the wrong section, if this is a duplicate, my apologies.