Currently you can update certain areas of a ticket using the update_many API endpoint
PUT /api/v2/tickets/update_many.json?<ticket_id>
but not when updating a ticket using the single ticket API endpoint
PUT /api/v2/tickets/{ticket_id}
It does not make sense that I can update a field value using update many and not the individual ticket endpoints.
For example, when updating a ticket using the tickets API, the instruction to add additional tags is being ignored when doing so for the single ticket endpoint but is accepted using the update_many endpoint.
Thanks for sharing your question with the Community! You should be able to make those property value updates using the individual ticket update endpoint. The only difference between Update Many Tickets and Update Ticket is that Update Many automatically checks for ticket update collisions. With Update Ticket, you would need to include those safe guards yourself to prevent conflicts. Have you tried making the Update Ticket request with those specifications? If not, you can see how to do that here.
Best,
Erica