Safari browser windows closing for no reason

[iTurbo]

I'm having a problem with Safari mysteriously closing the browser window. It just disappears, sometimes even trying to load macrumors.com. Safari stays up as the active application, but I have to open a new window and try again. This seems to be happening more and more lately.

I wouldn't say it's a 'crash' since Safari stays up and continues to work after I open a new window.....but it is annoying. What gives?

 

[Gregg2]

Not enough information.

Sounds like it happens on various sites, so it's not due to a particular web page.

But, you list several Macs, don't say which one is experiencing the problem, and do not identify the version of Safari or the OS. No one is going to be able to help you without that unless you get very lucky.

 

[iTurbo]

Ah yes I should have included that.

Details on setup this is happening with:
Late '12 iMac 27" (13,2), quad core 3.4GHz i7, 32 GB RAM, 1 TB Fusion Drive, GeForce GTX 680MX (2GB) graphics
MacOS 10.14.2 (Mojave w/APFS formatted stock Fusion drive)
Safari 12.0.2
Usually nothing ever connected externally except for my iPhone 7

It does seem to happen randomly at any site. I am not big on using tabbed browsing for whatever it's worth. I will open multiple tabs and see if it closes everything next time it happens. Safari continues to run, I just have to open a new browser window and try again, so I can't really say Safari is 'crashing'. It happens a few times every day.