Fault must lie somewhere else and it'll need to be traced.
I know this answer sounds kind of hinky but one of the cable looms that is fed from this fuse may have a short somewhere. Fuses blow when there is an increase in current greater than the fuse limit. Find the short and find the fault.
Have you added anything to the car that meant you were accessing the fuse box? Could some wires be crossing?
Have you added anything that is taken from the side lights supply and could have increased the current flow through that fuse?
Is it the correct fuse rating? Check the back of the fuse panel cover to make sure the fuse is of the correct rating.
HTH
Keith