I am also having slowness problems. If I type one letter it takes about four seconds for it to appear. If I type many letters rapidly, it takes four seconds and then they all appear at once. This is on a 2017 MacBook Pro running MacOS 10.15.7 (19H114). I am also running it on an iPad and have very similar problems on there too. On both devices I have deleted the app, rebooted, and reinstalled it, with no change in the behavior. Evernote Web works fine.