If on the Mac ecosystem, Bear is Apple notes but with fewer sync bugs and more useful features (like a close cousin of markdown and amazing tagging). I've switched to that for notes that might stick around for a while (from Evernote and Apple notes, though I still forward emails into the former as a convenient archive). For transient notes (like shopping lists etc.) I just use drafts on iOS. Seems to work for me afte…
I'm not sure how long ago you tried Apple Notes but I've use it all the time now after trying many apps. I don't have any sync problems and it has good support for images, pen input, tables, styles etc. For anything more technical I use Quiver which supports MarkDown, code with pretty printing, LaTex and diagram markup, but it doesn't have an iPad editor (just reader).
From various Apple support forum requests it seems that a lot of people were having similar - but also a number were totally unaffected.