The previous owners of my b37cr had installed an additional seawater strainer between the vapour lock & the engine (I have no idea why!) Not long after a bought the boat, the filter broke, just as you have described. Think that this was an original product I replaced it "like for like", only to be told by my mechanic that it is not an original setup, and the strainer was not made for the water pressure created by the water pump. It was immediately removed.
My comment is to check that your strainer is rated for the pressure.
Steven
SV Konan