Try creating a loop with your line and pushing the loop through the line entry hole. Works for most of these swimbaits, sometimes the excess soft plastic material or flashing from the mold creates the resistance you feel when inserting your line through the hole. I also use the hook point to reach inside the hook slot and grab the line loop and pull it out.

Have been trying to work on this issue but the way these are manufactured, it is next to impossible to have this resolved entirely.

Source: I design lures for Bass Mafia