You’re welcome.
I have noticed a similar issue, relating to 3 posts - though not directly related to your issue - I wonder if it might have a similar effect.
If I reply in a topic to the same person for a third time (even if it were days or hours apart), it suggests that I might consider using a Personal Message. Which in the context of a support forum isn’t a great idea as the answer may well help others. So I just ignore it, but it allows the post.
However, yours differs in that for the most part it would look like you are making multiple consecutive posts in the one topic.