Former President Obama is not happy with President Trump due to the tweet accusations of illegal wiretapping last weekend. President Trump called Obama to say thank you for a letter Obama left in the resolute desk, as per tradition.
Initially, the pair seemed to be friendly during the transition phase and inauguration. Obama even offered to help consult Trump on the presidency during his first few months. Then, on January 30th, Obama showed his support for the maniacal anti-Trump protests. And, as you can imagine, everything went downhill since then.
This is from the Washington Examiner:
The two presidents promised to have a good relationship and seemed at least outwardly chummy during the inauguration. Obama had even offered to consult for Trump on the presidency during his first months to help him deal with the pressures of the office. But, it appears that is now on hold and the traditional relationship between presidents is on the rocks. Usually, current presidents and ex-presidents show some deference to each other in order to uphold the decorum of the office.