Operation Cuba Libre is still underway. First hand reports from our radio operators are indicating that their stations are being jammed, individually, shortly after beginning their transmissions. The Cuban government is actively trying to circumvent our effort as are working with the Russian and Chinese governments to hit this site with a series of attacks. We’re still standing, as we always will, in the fight for freedom. -NCS

Is someone from Cuba jamming the 40 Meter band?
It sure looks like it. There is compelling evidence presented by Josh Nass of Ham Radio Crash Course that a jamming signal is originating somewhere in Cuba.

Using directional finding software and a variety of web enabled SDR stations, he was able to show the high likelihood that the originating source is Cuba.
Here is an additional write up on how this works.
Direction Finding with TDoA on KiwiSDR Net: An Introduction
If Cuba can jam signals, certainly others can.
Get trained.
Have a plan.
Practice often.