For the record, I’ve ran into the same issue. April 2018 build, 33k miles. Started as an intermittent issue, which I originally blamed BT / the app for, but it became more common and now 100%.
Mobile service scheduled.
My trunk wouldn't open from app, car screen or physical button.
Booked mobile service to come within 1.5 wks (Vancouver, Canada)
Service came and they brought the wrong parts, whoever handled the service request assumed it was the frunk even though in my description I only said trunk (in hindsight i should've said BACK trunk). He did a diagnostic and determined the trunk data wire was not sending a signal so it needed to be replaced. Luckily the tech said he had the part at home and would go do a quick repair for another customer first and come back after hours to fix my trunk.
He came back and it took about 1.5 hrs for him to replace the entire trunk cable bundle, see attached pic.
I feel the service guys really want to help fix customer issues, maybe it's cause they get OT pay or bonuses? Anyway, I was very impressed it was the first time I've used the mobile service.