Issue recognising word after change to sentences.ini

Hey there,
I have a timer intent that I tweaked recently, and after doing so, my “stop” intent stopped working. I can’t really figure out what is going wrong here, so I’d appreciate any hints you might be able to give me.

First, my timer intent looked like this:

\[set [a]] [<timer_type>] timer [for] <timer_expr> 

(example: “set a sleep timer for 15 minutes”)

This worked fine, and “stop” was recognised correctly.
Now I added this additional rule for my timer intent:

<timer_expr> [<timer_type>] timer

(example: “15 minute sleep timer”)

The new rule to set a timer works great. The old rule also still works. However, for some reason “stop” is no longer being recognised. Instead, when I say stop I see that the ASR consistently recognises “sleep timer”:

[2021-11-19 15:10:13] [Asr] was asked to listen on site default
[2021-11-19 15:10:15] [Asr] captured text 'sleep timer' in 1.2091278880002392s on site default
[2021-11-19 15:10:15] [Asr] was asked to stop listening on site default

Any ideas what might be going on here?

For reference, here is the full timer and stop intent code:

timer_one_to_nine = (1..9)
timer_one_to_fifty_nine = (1..59)
timer_two_to_fifty_nine = (2..59)
timer_hour_half_expr = (<timer_one_to_nine>{hours} and (a half){minutes:30} (hours | hour))
timer_hour_expr = (((one:1){hours} hour) | ((<timer_one_to_nine>){hours} (hours | hour)) | <timer_hour_half_expr>)
timer_minute_half_expr = (<timer_one_to_fifty_nine>{minutes} and (a half){seconds:30} (minutes | minute))
timer_minute_expr = (((one:1){minutes} minute) | ((<timer_two_to_fifty_nine>){minutes} (minutes | minute)) | <timer_minute_half_expr>)
timer_second_expr = ((one:1){seconds} second) | ((<timer_two_to_fifty_nine>){seconds} (seconds | second))
timer_expr = ((<timer_hour_expr> [[and] <timer_minute_expr>] [[and] <timer_second_expr>]) | (<timer_minute_expr> [[and] <timer_second_expr>]) | <timer_second_expr>)
timer_type = (meditation:1 | sleep:2){type}
\[set [a]] [<timer_type>] timer [for] <timer_expr> 
<timer_expr> [<timer_type>] timer
play (nature:2){type} sounds for <timer_expr>


Actually I now notice that “sleep timer” is also consistently recognised when I say absolutely nothing!
This is so odd!