Bearings need oil pretty often. Surprisingly, spool bearing throw out oil with every cast. Mix in rain, dust, sand or a plunge in the river all are reasons to add a drop or even clean out for the plunge. Water and sand are the enemy of reels. If you are using grease in all other non-spool bearings, and sand or water has invaded, it’s time to start over with a full cleaning and lube. Many of the high end oils are thin. For a good reason! But they need regular oiling for maximum performance. Remember spoil bearings need (1), one, uno drop each.
How Often Should a Fishing Reel Be Oiled?