Thanks for reporting. CC @golang/release.

First, can you try and see if you're able to start slowbots by including a Cq-Include-Trybots: luci.golang.try:gotip-linux-loong64 git footer in the commit message, as documented in the "Blocking" bullet point of https://go.dev/wiki/SlowBots#using-slowbots. If that works, that'll confirm that workaround is available, and that this problem is to do with the frontend UI of Gerrit.

Second, the error message suggests to see browser console logs, can you see if there's a relevant error message there that might help explain this?

I suspect there's something going wrong with the Gerrit UI frontend that triggers the API call when you press the "Add" button. It's unclear why it only affects that dialog and not others. But Gerrit has a button in the top right corner to report a bug, which might be the best path forward if we confirm this only affects the dialog and not the Cq-Include-Trybots approach to triggering slowbots.

The SlowBots builder on linux-long64 is offline and I am currently unable to perform testing. However, I have checked the browser console and received the following error message:

buildbucket.js:862 Failed to schedule builds: Error: "user:abner.chenc@gmail.com" does not have permission "buildbucket.builds.add" in bucket "golang/try"
    at buildbucket.js:862:34
    at Array.forEach (<anonymous>)
    at module$exports$google3$third_party$java_src$gerritcodereview$plugins$buildbucket$web$cr$2dtryjob$2dpicker.CrTryjobPicker.scheduleSelectedBuilders (buildbucket.js:862:5)
    at async module$exports$google3$third_party$java_src$gerritcodereview$plugins$buildbucket$web$cr$2dtryjob$2dpicker.CrTryjobPicker.onAddTap (buildbucket.js:862:284)
（匿名） @ buildbucket.js:862
Promise.catch（异步）
handleAddTap @ buildbucket.js:862
handleEvent @ buildbucket.js:741

My gerrit account started using abner.chenc@gmail.com registered, later added chenguoqi@loongson.cn and has been using it all along chenguoqi@loongson.cn This email.

Gentle ping.
Thanks.

It's unexpected that the error includes a different email than your primary Gerrit email, the one visible at https://go-review.googlesource.com/dashboard/54019. I'll look into why this might be happening, and for now I've added your second email to project-golang-may-start-trybots to unblock you.