During two seasons of La Casa de Papel, Lisbon was working against the Professor while he tried to apprehend the thieves. However, after falling in love with the teacher, she decided to leave Spain and move to Thailand.
Things were going well until the third season of La Casa de Papel when the professor announced that they would rob the Bank of Spain to rescue Rio and Lisbon was forced to help.
A fan of La Casa De Papel pointed out that the professor and Lisbon are in love and that something catastrophic would have to happen for the couple to separate. Meanwhile, another noted how Alvaro said that the main driver for him was revenge.
The House of Paper theory describes that something could happen during season 5 that causes a major sequel, such as Raquel betraying her or refusing to follow through on her plan.
While I see the professor as a vindictive person, it would be surprising if he also has some more honorable reasons for doing both heists at La Casa de Papel.
Could Lisbon betray the professor from within the heist and bring out a side of him that has yet to be seen by La Casa de Papel fans? It is something that we will only know when the expected series is on the Netflix platform.