Adams Barrow promises to step down after a 3- year term, but now he is changing his mind and planning to run for the upcoming
That is maybe why Jammeh want to go back home and vote ,

Gambia’s Jammeh Seeks Return to Nation He Ruled For 22 Years
By Modou Joof
January 11, 2020, 9:25 AM EST
Exiled ruler wants international bodies to enforce 2017 deal
African nation of 2 million people will hold vote next year

Gambia’s exiled former dictator, Yahya Jammeh, is seeking his political party’s support to return to the West African nation he ruled for 22 years.

The Alliance for Patriotic Reorientation and Construction party is already planning a protest calling for the United Nations, the African Union and the Economic Community of West African States to follow through on their commitment to ensure Jammeh could return to Gambia, its deputy leader Ousman Rambo Jatta said by phone Saturday from the capital, Banjul.

The international bodies included the clause that he could come back at “a time of his choosing” in a January 2017 deal to end the month-long political impasse triggered by Jammeh’s refusal to step down for the winner of a December 2016 vote, Adama Barrow.

Jammeh, 54, has been living in Equatorial Guinea ever since a regional armed intervention enforced the election result. Barrow is expected to run for re-election in 2021 despite an earlier agreement to step down after a three-year transition period. Gambia, home to about 2 million people and surrounded by Senegal except for its access to the Atlantic Ocean, has never had a smooth transfer of power.

https://www.bloomberg.com/news/articles/2020-01-11/gambia-s-jammeh-seeks-return-to-nation-he-ruled-for-22-years