Tested using Combined Arms to check reload timers after expected reload time was exceeded in SA-19, SA-15, SA-9, and SA-8. Testing shows that this only occurs in large servers, such as Greyflag and Contention. I was unable to replicate the issue using small multiplayer test servers.
A three-step workaround (using Combined Arms) has been developed:
1) Disengage vehicle handbrake
2) Interrupt reload process
3) Restarting reload using Rctrl+\