A few ideas. I had a rupture valve iterm give me issuses until one day it failed for good w/ an entrapee, that was a fun one, but I finally found the problem after numerous calls w/ a stld fault. Also you could have a low pressure sw acting up or a sticky packing, check your down leveling speed, those otis packings are known to be a bit troublesome. The down direction limit sw's also could be a possibility.
