In that log I don’t see any “text” streams in the final video. Looking at the logs I see you’re using a custom profile and in your profile you’re specifying specific stream mappings which may be causing the havoc:
→ ffmpeg-audioac3=-map 0:1 -map 0:1 -c:a:0 copy -c:a:1 aac -ab 192k -ac 2
MCEBuddy dynamically calculates the streams to copy based on the stream layouts after the remuxing is completed. You should not specify stream mapping or if you’re doing so then disable remuxing because the stream mapping can change during remuxing. The default profile won’t carry the “text” stream, they will either extract it or ignore it.