Yes, there has been no explanation.

However, the rumors will appear in the rumor later. . .

The following is the news on the Internet:

The other two episodes of the side story will be released on DVD on July 21, but British Sky TV claimed that they will be released on May 26 (local time) ) was aired first, but it has not been confirmed. Please stay tuned~!

The two additional episodes of "Prison Break" are titled "The Old Ball and Chain" and "Free" respectively. They feel a bit like a TV movie and have independent stories. The plot takes place in the fourth season. A few days after the finale, FOX revealed that this was "a very difficult escape challenge that Michael faced alone" and that Gretchen would appear again in the show.