Messages with domain name links are being blocked (incoming and outgoing): How to fix?

I have a T-mobile account under the plan: ONE Plan Military Business

I own a small business and own many domains, including:

gardeningbees.com
ncgardening.com
serverscience.com

I am presently no sending out any automated messages. I send only messages manually using the default messaging app on phones with the numbers above to friends, family members, and a very few people who have asked me to share gardening information with them. And, the volume is exceedingly low: at most less than 10 messages per day.

Those messages are being blocked whenever I include any of the above domain names as part of the text (with or without https://).

There is no spam associated with my messages. Mostly, it is to share gardening information that people have asked that I share with them. I am a Master Gardener Volunteer in training in Wake County, North Carolina, and will be answering community questions and sometimes will need to follow up when a person asks me a gardening question that I cannot immediately answer. I'm doing that already, but not as a Master Gardener (until I complete my training) and am answering community questions on my own.

I talked on the phone with T-mobile, but nobody could figure out why this is happening. Is the problem because I have a business account with T-mobile? More importantly, can you fix or advise me to to get this issue resolved?

Many thanks for anything you can suggest or do to help!