I hope everyone can hold their respective horses here - OP - I'm sorry, but as you well know there is no one on this site who can know with an certainty what your spouse is up to, if anything. It is still hard to hear people talk with such assurance, but do to try to listen to some of the advice, even though the "I'm sure" and the "I know" or "I can guarantee" are not actually possible.
I have read this thread, and especially your responses to it, and a few things stand out to me:
1. You have engaged in some rug sweeping in the past. And you are aware of that.
2. You are not willing (or do not want to for whatever reason) to revisit/dig into that past now with your spouse now.
3. You really hope you are wrong about your spouse's behavior.
4. You feel like something is off, and while you are not sure what it is, it seems possible that a new A (or continuation of an old one) is potentially the cause for your concern.
The reason why people are suggesting a back-dig into the past is that you rugswept. I'm guessing because it was more comfortable for you both. And the one thing rugsweeping does is leave a massive pile of unresolved crap under the marital rug. It's still there, lurking, meaning that whatever caused it is still there too. My WH and I did a rather deep dive into his A (which started in 2017 so not that much further back than you) relatively recently (sometime earlier this year). I can tell you in all honestly that his willingness to be so open and talk about those things is really why we still speak at all now.
And maybe, just maybe, some of your spouse's behaviors are innocent, and their connection to that past is really what triggered how you feel now - the suspicion, and that shitty tightrope in your stomach feeling - maybe it all comes down to a trigger from the past. If that is all it is, and that nothing untoward is happening now, then even more reason for you to revisit those things - so you can move forward in relative peace.
Being able to talk about those things really is the key to having any chance at successful R IMO. Had my WS not decided to commit to IC and to figure what was (in his words) "completely wrong" with him that he could behave the way he did, my only options were continue to live the cycle described above, or leave. Why? Because my WH, prior to his intensive and lengthy IC, which was well after I filed to terminate our relationship, also had rules for our relationship going forward that included some level of secrecy. While there were no locked phone folders my WH felt completely entitled to get mad if I had the nerve to infringe on whatever level of privacy he believed he should have by asking where he went after work or who he had been talking to on the phone - things I would have done before the A all of a sudden were massive affronts to his independence. That did not help me - and it did not help US. Your spouse isn't helping you either, even if she is totally innocent right now.
So I think you should trust your gut and do what you need to re finding out what, if anything, is going on. But, if you get to the point you are satisfied that nothing is, I still think that past needs to be addressed. Living with that queasy feeling, even if it's not very often, is no way to live.
[This message edited by ThisIsSoLonely at 8:58 PM, Tuesday, August 13th]