SendCaptions not working

Operating System Info

Windows 10

Other OS

No response

OBS Studio Version

27.0.1

OBS Studio Version (Other)

No response

OBS Studio Log URL

https://obsproject.com/logs/oeSC2zsH3QUec5sK

OBS Studio Crash Log URL

No response

Expected Behavior

I am using websockets to send captions. Websockets uses SendCaptions to send the caption.

The caption builds one word at a time.

I have set the system to send captions at long intervals for test purposes.

I would expect the captions to appear on the video correctly.

Current Behavior

Captions should appear in video output. After a few seconds the output fails, as follows:

Sending the following text works:
This is an automated test caption from your captione

Sending the following text works:
This is an automated test caption from your captione

Sending the following text does not work:
This is an automated test caption from your captioner

etc

The problem appears to be linked to the number of characters in the line and can be repeated fully. I haves tested with Youtube and Facebook

Steps to Reproduce

1. Using SendCaption sending the following text works:
   This is an automated test caption from your captione

2. Sending the following text does not work:
   This is an automated test caption from your captioner

Anything else we should know?

No response

Start by reviewing the SendCaptions path and the linked OBS Studio log, then trace how captions are passed through the websocket interface and video output. Reproduce the boundary between the working and failing caption strings using OBS Studio 27.0.1. Done means captions continue appearing correctly when the line reaches the reported character length.