MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports) Battery - Condition: Service Recommended

How is this possible, and any solution pls? Thanks

This happened after the Big Sur update!

2.3 GHz Quad-Core Intel Core i5

8 GB 2133 MHz LPDDR3

Intel Iris Plus Graphics 655 1536 MB

250.69 GB (250,685,575,168 bytes)

  Full Charge Capacity (mAh): 3859

  State of Charge (%): 100

  Health Information:

  Cycle Count: 321

  Condition: Service Recommended

How is this possible, and any solution pls? Thanks