arc fault breaker keeps tripping

hello,
i am trying to install ARC fault circuit breaker but it keeps tripping
because the neutral wire that's supposed to connect to the ARC fault
breaker is not dedicated but is shared with another non arc-fault
circuite breaker.
Some one told me that both circuit breakers that share the same neutral
wire need to be ARC Fault breaker. Even if this is true, arc fault
breakers are expensive so I hope that there's another way to fix this
problem.
PS I have tried running a neutral wire from the Arc Fault breaker to
the neutral bus and of course the breaker still trips.
Thank you in advance for your help.