Fire stick audio sync issues

I have alot of issues with Alexa multi room music app… There is significant lag in the echo dots, which causes music to be out of sync with the fire stick and media center… I’ve tried everything… They have an av and lip sync tool in fire stick,but when u get the song to sync up, the very next song will be out of sync… I’ve gotten new devices, changed internet company, changed router, changed Amazon acct… Nothing works… also tv is Samsung with optical to Bose receiver…Please help