It’s possible somehow the phone isn’t working where it may work elsewhere. Try installing Yoroi on a reasonably secure browser, one that has no other extensions added and is on a system you’re sure is free of malware. Is your phone capitalizing any of the characters of the words by chance? Like an auto-correct maybe in your keyboard is altering the words you type in the app? That would probably cause this type of error.
im having the same issue i have recovered my account fine on pc but for my phone after i put in the 15 words the bottom restore button doesnt highlight at all have repeated putting in the words a dozen times
while im happy i got some version of my wallet restored im not home on my pc all day i really need it on my phone - have contacted support but trying to find the solution myself as well