I'm on Verizon in USA. My S9+ still had January 2019 security update. Talked to multiple agents but couldn't figure out why I wasn't getting updates. Tried Smart Switch, VZW assistant, but no luck. Downloaded firmware from SamMobile and flashed via Odin. Lost some settings although I backed up everything with Smart Switch, but some nice updates that I'd been missing.
Thanks for your inquiry. Once available, updates are released to Carriers and thereafter, it is at the Carriers discretion to release the update to customers. Since updates are released by Carriers in waves, we’re unable to determine when your device will receive an update. We appreciate your loyalty.