Weird speech added to end of my APIs

Hi, my APIs have started to act a little weird. An example API call is below, but the avatar comes with an extra bit of text at the end: "break time equals 0.25 S forward slash"

Below the JSON body for the API is the subtitle response, where you can see the additional text added.

Is there a way to prevent this weird text being added to my API calls? Thanks!

API body:

{
"source_url": "https://ada-dev-1.peakindicators.com/ada_avatar/avatar.png",
"script": {
"type": "text",
"input": "After applying the forecast over 3 periods, I project the number of 103,022,750 will be reached by March 2024. All revenue figures are in AED.",
"subtitles": true,
"provider": {
"type": "microsoft",
"voice_id": "en-US-JennyNeural"
} },
"config" : {
"stitch": true,
"fluent": true
}
}

SRT subtitles:

0
00:00:00,009 --> 00:00:02,819
After applying the forecast over three periods,

1
00:00:02,829 --> 00:00:10,100
I project the number of 103 million, 22,750 will be reached by March 2024.

2
00:00:10,859 --> 00:00:16,959
All revenue figures are in A E break time equals 0.25 S forward slash.