Just replying so that I, too, can receive replies to your inquiry. My problem may or may not be the same -- but pretty sure it is. I opted to use a 3rd party email app (TypeApp) which had a checkbox to be used for ActiveSync. When I add my Hotmail account with ActiveSync checked, it pulls in my contacts etc into the native (Samsung) Contacts app. But when I edit an individual contact, it does not give me the option (normally under "View more") to edit ringtones and texttones. The options are simply not present. When I created my email account *without* ActiveSync checked, no contacts were pulled in; it was simply email. I also added a Gmail account and *was* able to use custom tones. After various online searches and several forum boards, I've come to the conclusion that the problem is almost certainly with Microsoft/ActiveSync. So, can you provide any insight into this issue? Note, I was able to have custom ringtones etc on my previous phone (LG V20 running Nougat 7.1.2). But I was using the Outlook email app. Hmmm, interesting.
I have same problem. Some contacts - I can use edit and Ringtone is an option - at the moment I have three specific Ringtones. Default ringtone is set and works for all the others. For most contacts if I use Edit there is NO tag/selector to add Ringtone. Really annoying! I suspect at first the 'Contacts' were OK and individual ringtone could be set for all individual people and then it 'broke'!
At the moment I miss my Windows phone!
I have exported contacts into a 'contacts.vcf' file and edited - no contacts in this exported file have mention of Ringtone.
Strangely, since finishing this post, I have discovered that if I group people then I can assign Ringtone to the group. And weirdly if I go to each contact in the group I can edit their ringtones.
A solution of sorts! Check groups - all my Contacts had turned up in Family. I think once a person is not in a group can assign a Ringtone.
I have found(accidentally) that by installing the BlackBerry contacts app, the Samsung contacts app thinks that the BB contacts are on the phone and then you can give then custom ringtones.
Very strange, but this is another reason that I miss my BB Z30.
I was tempted to install another contact management, but at the moment shy of introducing more complication, and note your choice of Blackberry contacts app.
Putting people into groups where I can then assign ringtone has sort of worked - albeit you have to keep tidying groups as many end up in Family! So I guess groups and ringtones cannot survive the Android vs Microsoft synchronisation.
I've read that the best solution is not to synchronise phone with other Microsoft devices - see http://www.locktar.nl/general/edit-outlook-com-contacts-android/
At the moment, fingers crossed, I am hoping that my Samsung phone, Windows Phone and computers will stabilise. Fortunately, my Samsung phone has not corrupted my Microsoft devices.