Range.Find with merged cells

I keep getting completely random results using the .find method with a sheet containing merged cells:

I've tried all combinations of
xlpart, xlwhole
xlvalues, xlformulas
expanded the range to include the merged cells
set range as all column A, column A & B

but I can't get it to work consistently, if at all.

I could get it to work if I searched the whole sheet without specifying a range, however there are likely to be more instances over time so I don't want it to find them as it will screw up the range.

I know merged cells are an absolute pain, however they need to remain that way in this case.

Thanks