usually when there is a sequencing problem with the cylinders in the mast it is either something binding the channels or an internal cylinder valve problem.

check the mast closely and make sure all the rollers are ok, not broken or damaged and make sure the channels are clear of debris or any other obstruction that may cause them to hang up.

Then each cylinder will have to be removed and dissassembled and checked. Start with the center cylinder and once dissassembled check the safety valve in the piston and make sure it is intact. Do the same for the outside right cylinder also and if no problems found move to the left outside one.
In most cases i have found that the safety valve in the piston has come apart in the center cylinder causing the mast to malfunction and cause the exact symptoms you describe.