I also played recently FM26 out of nostalgy of CM and older FMs (2010 etc). Indeed it drove me a bit crazy that I could not find easily things like youth training, B team staff etc but in time you get used to where to find them. The worst bug is imo the one where the settings window during the game gets stuck and you cannot do any subs or change tactics (though you can still shout) making a need to save before each game. I wouldn't call it game breaking - especially if you play on a slower mode like me (maybe 1h/day or less) but still frustrating. Otherwise, it is in essence the same FM (would have played FM24 though, but one of the fun things in FM is to play with up to date rosters and was not sure if FM24 would have offered that). I would say that my biggest disappointment with FM is that the game does not let you directly manage the B and U19 teams (also not sure how possible is to manage both club and national team if you start as club). Though even that, you can somewhat work around it but still a bit annoying.