Thank you so much for you post, I apologize for getting back to you so late but I wanted to let you know that based on your trigger map, we may need to have you set up a brand new trigger that is dedicated to triggering a build on “tech/my-branch”, this can happen on your workflow editor under the Triggers tab. Should you already have this configured and it is simply not showing up on your trigger map, we can definitely take a closer look which we can offer by you submitting a support ticket Bitrise - Mobile Continuous Integration and Delivery - iOS & Android Build Automation.
Let me know if this helps or if you have any questions on the above!