I'm having the same problem with my BC purchased last summer.
I recently had a Lyman 17AUG (.584) sight put on it. It now shoots too high but still to the left, even with max adjustment of the rear sight.
I've ordered (on backorder) a Lyman 17AML (.494) which should be OK for the distance I shoot (63 y/o eyes). After that's put on and again bore-sighted, if it's still shooting to the left, I'm sending it back also.
NOTE: When visiting the H&R Repair webpage, I noticed that there's now a link at the bottom to track your repair.