Flynn's 24-day tenure as National Security Advisor was the shortest in the 63-year history of the office.[15]
Those communications he had with the Russian ambassador were subsequently leaked to the press.[120]
Commenting on Flynn's resignation, on February 14 White House Press Secretary Sean Spicer stated, "We got to a point not based on a legal issue, but based on a trust issue, where a level of trust between the President and General Flynn had eroded to the point where he felt he had to make a change ...
The issue here was that the President [Trump] got to the point where General Flynn's relationship – misleading the Vice President and others, or the possibility that he had forgotten critical details of this important conversation had created a critical mass and an unsustainable situation.
That's why the President decided to ask for his resignation, and he got it."[121]
The Russia Hoax was originally aimed at Flynn, not Trump.
https://chicagoboyz.net/archives/59533.html
I am no Flynn fan but they way he was pushed out by Pence smacks of palace intrigue. Pence is a loyal GOPe and not one of the MAGA good guys, IMO. Flynn was with POTUS way before Pence parachuted in and was one of the few early supporters given a major role in the Trump admin.