Hi Mathieu,
Roon picks up data from various databases and assigns credits as provided by those databases (if you look at the credits or « About » section in settings you will see a list of licensors and database providers which change over time but include for example amongst others MusicBrainz). If you want Roon to ignore such data and focus on that from your tags you have 2 main solutions: you can go into « Settings » into « Library » and into Import Settings and there you can specify if Roon should prefer its data or yours or merge the 2 by credit type but beware that this then becomes a rule applied to all your albums. Alternatively if you want to remove credits on individual albums, you select the album and remove or add credits to that album alone (or multiple albums if you select more than one). Be aware that credits thee kept at both an album level (click on the three dots near the album title once in the album and look for the credits section) and at a track level (select the tracks you want to edit in the album page -or all of them if that is the case-) and you can also add or remove credits there (sometimes you have to edit credits at both levels). As a general rule if you are manually editing credits within Roon, best to do it a track level, even if you select all of them in one go.
Roon will not modify your tags but will rather store the information in its database on your system, so make sure to have automatic database backups set up so that they are not lost!
As regards the issue I brought up on naming convention, from inception until a few months ago, Roon followed the English naming conventions for artists as applied for example by All Music Guide or MusicBrainz or Discogs too. This does not make much difference for most modern music artists or living artists as they set what stage names are used for them but it matters for ensembles or historical artists where naming conventions were not so well established or for translations of non-latin names, particularly Cyrillic names.
Roon now adopts what it calls the original language name which is a minefield in the classical world where other considerations have stepped in over the last decades and which is a big problem for ensembles. If you are Polish it is « Fryderyk Chopin » that is the original name but if you are French or English it is « Frédéric Chopin ». If you are Catalan it is « Pau Casals »; if you are not or look for a recording in a shop or online it is « Pablo Casals ».
Orchestras known as the Warsaw Philharmonic Orchestra or the Turku Philharmonic Orchestra have names in Polish or Finnish that non native speakers will not recognise and which they do not use when touring outside their home countries.
Conductor Vladimir Jurowski now appears as Vladimir Mikhailovich Jurowski whilst in London when performing as head of the LPO or when represented by his agent; as his father Mikhail Jurowski is also a conductor adding his middle name is confusing rather than clarifying.
The translation of Russian is also a function of where artists may have lived or your choice of dominant languag: the canonical for Shostakovich in French is Chostakovitch and for Tchaikovsky is Tschaikowsky is German for obvious linguistic reasons. That diacritical marks are now always shown (accents to you and me) is much less of an issue (those that matters to the phonetic pronunciation of a name were usually shown previously as opposed to those that are about emphasising a syllable in the name).
Now I have no issue with allowing people to select seeing names in original language but why reduce options when those are in any case still functioning in the background? By having menus by language Roon had been going the way of being more customisable for non-English users, whilst this change does not help for consistency or understanding and goes in the contrary direction. If I am a French speaker only (I am bilingual French and English and a good German speaker too), I would rather an option to see artist names in their French incarnation.
It is of course a complicated situation in the classical world as while some ensemble names may be translated (eg general the Vienna Philharmonic), others are not (the Dresden Staatskapelle or Leipzig Gewandhaus).
In any case if you have your own library of music beyond any streaming service, if you want your composer or artists or performer tags to be recognised, you should follow the AMG naming conventions even if they differ from what Roon may show as Roon will recognise them. Otherwise unless you know what Roon has decided is the « canonical » name for which there is no master list, the name may not be recognised and it will not be linked to that artists in a search.
Apologies for the long diversion and any typos (too late to check). In general Roon listen to their community (I must say that I did not see any request for the change they made nor was it announced or explained until a month later) but classical tends to be overlooked or often misunderstood or not to have been thought about when changes are made or protocols adopted, hence all the problems with the way metadata tags were defined…lol