Uneven soundstage help, please.

Whats your primary source?  I ask because I’ve been playing around with Sonarworks Reference 4.  Its a dsp room correction software and does some cool stuff.  Another option for dsp is dspeaker antimode.

As far as your setup, is this the same amp you were using with your prior speakers?  You ought to run down the list of things to do in order to check for something in your chain not working properly.  Interconnects, speaker cables, all you connections are tight, speakers are wired in phase, distance from the listening spot to the right and left speakers is identical, same degree of toe in for left and right speakers, speakers are level and the same height?

Impossible to ascertain DIY and especially remotely. A professional tech look-over and analysis required on your source AND/ OR integrated amp

Before you do that, eliminate the other variables wherever possible

(1) swap in your other speakers .... is the same issue still present ?. If yes, then it’s highly likely of a new FUHBAR in your upstream source and/or amp.

(2) Swap in an alternate source .... repeat exercise. If it’s still there then it’s highly probable that your amp that needs to be serviced. 
I had a new comparable issue with an intermittent output FUHBAR arising suddenly in my “C” system integrated amp. It still worked but with an intermittent partial loss of output in one channel.
I took it in to a professional tech who tested it on his bench and quickly diagnosed the issue that was not visible to my naked eye. It was a failing output solder joint that was intermittently arcing ... that was a cheap and fast $100 fix .

GOOD THING I DID IT .... This was no DIY matter and not an item to ignore .... it was a potential fire hazard waiting to happen .

FWIW

distance from the listening spot to the right and left speakers is identical, same degree of toe in for left and right speakers, speakers are level and the same height?

This! ^^

Foolproof method in oddball rooms, what I have done before including at CES so I know it works:
Pull a string to establish a straight line between the two speakers. Use a framing square to go straight off mid-line to your listening chair. This establishes your perfectly equidistant and symmetrical speaker/listener triangle. Proceed to tweak to find the right amount of toe in. This is Step One.

Step Two, listen and look. Asymmetrical room reflections will pull and smear imaging. How and how much, and what sounds it affects, all depends on the various room surfaces. So look around. Follow lines of radiation patterns

Yes it will sound a lot better if this is resolved. Because right now you're noticing the obvious effects. If you are able to correct them however then you will notice a lot of less obvious effects are also gone.

You mention the wife factor. There's some guys, and I use the term guys loosely in this case, who were triggered when I said we do things to please women. Apparently we are all such rugged individualists we never turn our lives inside out to please the dames. Or if we do we're too ruggedly stoic to talk about it. So probably you misspoke. But if you do all this alignment stuff and still want better imaging without upsetting you know who too much Synergistic Research makes these little wonders called HFT which she who doesn't factor in will probably not even notice if you put them on your speakers. 

Seriously. They totally work.

Well, to completely understand, you can’t move the speakers, and you can’t add better room acoustic treatments, like GIK Art panels which let you pick any artwork and put it on them.

Those are always my first two suggestions. You can try crossing your speakers in front of your head, minimizing side reflections.

Lastly, if none of this work it's probably becuase you are getting a very unbalanced frequency response.  Assuming it's not bad speakers, you will need to measure and adjust using EQ, either from a separate unit, or by using the built in EQ of Roon or similar. If you aren’t familiar with measurement and correction I suggest you get something that has room correction built in, like Anthem pre/receivers, etc. or a miniDSP unit with Dirac live built in.

Here's an example of how I corrected a much milder problem than you are having using the built in EQ from Roon:

https://speakermakersjourney.blogspot.com/2020/01/the-snr-1-room-response-and-roon.html

What you should do is pick a speaker with the least reflections around it as your baseline, and try to get your other speaker to match it.

If you use ARC, like Dirac or Anthem they will do it all for you.