The arrows locate the locking plate. It may be that someone has previously taken everything out and cleaned up/replaced things. A good idea to check the rubbers and alloy inserts if they feel a bit loose. If the rubbers wear, the alloy inserts also wear from moving around, and it is possible if bad enough that the alloy inserts will start wearing into the wheel. Easy enough to see the as rubber that locates the alloy inserts wears away, and the alloy inserts wear elongated.
Always best to replace the rubbers and alloy inserts as a set. Quite a bit of rubber dust can accumulate in there. Also use the right grease on the splines, and check the three o rings that keep the grease in/water out.
FYI, I have replaced the rubbers/alloy inserts once in 183,000kms, may be due again in another 50,000kms