First, please check the pins of the charger: if they move easily but are at a different level from each other, the problem may be in the charger. In this case, you can try using a different charger.
If the pins of the charging dock appear stuck and did not move easily, please check if there is any dust, dirt or clog around them and clean them.
If you find dirt or black dots on the band contacts, please try cleaning them.
For cleaning, you will need table vinegar with a concentration of no more than 10% and a cotton swab.
Dip a cotton swab into a small amount of vinegar
Soak the contacts in vinegar and leave them like that for 10 minutes, ensuring that the vinegar doesn't dry out
Rinse the contacts under running water while still rubbing the contacts with a cotton swab
Rinse the contacts again under running water without using the cotton swab this time
Dry the band with a tissue and remove moisture from the charging contacts by using a dry cotton swab
If this does not help, the problem may be in the device itself. In this case, please first check the band contacts. If you see any dust or dirt around them, also try cleaning them with a toothpick.