See #44018 for the discussion and the consequences.
To reproduce:
- install tsc 2.7.2
- create new folder
- change to folder
- tsc --init
- open VS Code
- create a HelloWorlds.ts
- Run Task > pick the watch task
- have auto save one
- change the HelloWorld.ts a couple of times. At some point the Building... in the status line doesn't disappear anymore.
The underlying reason is that the terminal sends lines twice confusing the tracking of the task output.

As you can see in the above screen shot the FIle change detected line at 11:13:12 is send twice resulting in the task to assume that two builds have started but only one compilation complete is send hence the building is kept.
See #44018 for the discussion and the consequences.
To reproduce:
The underlying reason is that the terminal sends lines twice confusing the tracking of the task output.
As you can see in the above screen shot the FIle change detected line at 11:13:12 is send twice resulting in the task to assume that two builds have started but only one compilation complete is send hence the building is kept.