(a) If a police officer who is receiving pension payments other than as provided in Section 3-109.3 re-enters active service, pension payment shall be suspended while he or she is in service. When he or she again retires, pension payments shall be resumed. If the police officer remains in service after re-entry for a period of less than 5 years, the pension shall be the same as upon first retirement. If the officer’s service after re-entry is at least 5 years and the officer makes the required contributions during the period of re-entry, his or her pension shall be recomputed by taking into account the additional period of service and salary.
     (b) If a police officer who first becomes a member on or after January 1, 2019 is receiving pension payments (other than as provided in Section 3-109.3) and re-enters active service with any municipality that has established a pension fund under this Article, that police officer may continue to receive pension payments while he or she is in active service, but shall only participate in a defined contribution plan established by the municipality pursuant to Section 3-109.4 and may not establish creditable service in the pension fund established by that municipality or have his or her pension recomputed.