Ah, audio/video drift.
Manufacturers and software engineers for some stupid fugging reason often use something called "variable frame rate" (VFR) recording. Video editors all use "Constant Frame Rate" (CFR). VFR is stupid, needs to go away, and is a bane to any editor. It sucks.
Anyway, VFR means you may set your screen to record at "30fps," but it's really recording "30, 30, 23, 18, 29, 30, 32, etc." "32" isn't a typo. VFR can record FASTER than the target frame rate.
Putting VFR media onto a CFR Timeline can cause all kinds of issues, including audio drift.
My friend, in my contract advisory work and tutorial creation I have literally dealt with thousands of people having VFR issues. Unfortunately you have two solutions. First, use a screen recorder that records CFR. Microsoft doesn't, OBS doesn't by default, but can be forced to. Second, you need to transcode your footage from VFR to CFR before editing. This is another step and takes time... But, since every fugging phone/tablet (except an iPhone/Pad Pro 13) ALWAYS records VFR, transcoding needs to happen a lot.
Yeah, Red, I know you don't use phones or tablets. That particular data is for the benefit of others.
Anyways, years ago I made a little video tutorial about VFR, how to check for it and how to fix it. I even added chapter marks.
Go right to 19:33 and learn how to use MediaInfo (free) to check for VFR. Next bit goes into using Handbrake (free) to transcode your videos. I even have handbrake settings to generate a high quality, fast performing file which were carefully tested by a buddy of mine. You don't need the rest of the video. That's for the kiddies who know fug all about digital video and need base principles.
Yes, yes, I'm potentially recommending more steps. Wanna avoid chopping into segments to avoid drift? I'm telling you how to do that.
Yeah, OBS is complex, but it's not TOO hard to learn, the YouTubes has tutorials, and, yeah, you're not needing its advanced functions for overlays, lower thirds, transitions, etc. You probably don't want to buy a hardware controller and set it up to bring in your overlays and text in real time as you record, but you could (my next tutorial series will be doing as much during recording as possible, because post gets old, so I have switchers and things to configure).
But OBS can record a MONITOR not a screen window, so switching between windows won't fug up the recording.
Yes, yes, there's a learning curve, but a little learning now will save time in the long run on fighting the Edit.
And it doesn't hurt you know a video editor guy who can give free advice via Skype.