UPNP server search & diacritics

[Gdg]

Hello.
I have this album: Amon Düül II-1969 Phallus Dei.
All the tracks, for both "Artist Name" and "Album Artist", are tagged with "Amon Düül II".
Using the Linn app (Android 12 tablet or IOS) or BubbleUPNP (Android 12 tablet) when I try and search this album by "Amon Duul II" nothing comes out.
Obviously this is just an example.

So, is there any way to normalize the accented / diacritics to the plain vowel or letter without fixing the tags?

Thank you for your help.