Tripping after several minutes many times is caused by incorrectly tightened connections getting hot which increases resistance and current draw. The loose connection could be at the breaker or at the connection to the A/C.
Note that if it "gets hot" that could result in a fire.
Being a licensed general contractor since 1979, I would first check the tightness of the connection at the breaker. Next, I would replace the breaker. Many panels for residential use are only listed for the brand of breaker which was originally installed. Try to match the brand (Eaton, Siemens, GE etc.). Almost all will fit and work properly, but technically is non-compliant if a different brand is used that is not listed by the manufacturer of the panel (again in residential work). I don't know what RVIA standard require.
If the replacement breaker still pops, then next I would check the connections at the A/C. This may not be within your skill level.
Hope you can fix this with a simple tightening of a connector or new breaker.