Due to licensing we are using per-user/legacy MFA in Microsoft 365. I noticed a strange issue just recently with the SharePoint app and PowerApps.
Android tablet - Open SharePoint app, go to site, and open page with a built-in PowerApps web part. The web part will not load. A "sign-in" button appears, but you can't click it. If you open the site in Google Chrome you will be prompted to sign-in and do MFA (accepted "Do Not Ask" for XX days). It worked in the browser. When I went back to the app it then opened up fine.
Any experience any weirdness with per-user MFA and 365 apps? Don't know of an easier way to get around this without having users open office.com to authenticate MFA and check the "Do Not Ask for MFA again for xx days".