Best answer by Bradley_Boost
I've slightly changed your topic so its easier for other users to find it as well as get the answers you're looking for.
Usually, communication issues can happen if the strongest mobile phone service provider in your area is having issues or major work done. These usually correct themselves over time. It will unlikely be an issue with the meter set up if they've be fine for 3 years and will no changes to the environment in this time.
It's always good to make sure that there are no problems with the meters though, so I'd advise you to reach out to the Boost team to check this out. Pop them an email to email@example.com or pop them a message via their Facebook page here!