Delayed Notifications

Hi all,I'm in Australia and have a 2 x flood light cams, 2 x chime pro extenders and 1 x video doorbell pro.My internet provider is great with speeds in excess of 100 Mbps and all devices have sufficient wifi signal. The chime pro extenders have made no difference to the network strength on my devices.Notifications on all devices are delayed, so much so that the devices are completely useless. Delays on doorbell are about one minute delayed and motion of my flood lights are almost as bad.My mobile phone is android, running version 10. I don't believe the issue is my mobile phone or internet provider. This has been an issue for at least 12 months and getting worse. Something needs to be done about this!