font selection in matrix table

I have created a matrix table, in the row field, I have added 6 reporting levels, when I drill down the table to level 3, the row headers look normal: level 1 and level 2 are in bold fonts, level 3 in normal fond. However, if I drill down the table to level 4 or level 5, suddenly all the row haders become bold, making it difficult to read.

Is there a solution to fix this? I.e., even if users drill it down to level 4, level 5, only level 1-2 are displayed in bold font.

ve selected 6 reporting levels. When I drill down the table to level