A sign was added to my SMS, even though I tested the SMS before sending it. Why?

[Sabina_B]

Hi community!
I recently sent out an SMS to 10K of our users. I had a link in the end of the SMS, when I tested it before sending, the link was valid. When I sent the SMS the day after, a dot was automatically added which made the link unvalid. Why and how did this happen? 

Disclaimer: It was no one else in my organisation that worked on this workflow except for me, and in the test SMS that I still have, there is not dot. Has this happened to anyone else?

[ramon_bisswanger]

Normally the real sendout should be the same as the proof SMS.

Do you have any personalization in the SMS content which could have an impact?