Sounds like you need to keep the key fob in a Faraday Box (metal) . We've had the same problem with the keyfob for the Honda CRV being too close to the rear hatch, and our cats would get in the garage and walk under the foot sensor, opening up the rear hatch quite by accident. our cats did like crawling in and sleeping back there. Putting the CRV key in a Faraday Box solved the problem. One can use an Altoids tin as a Faraday box, if need be.Not sure whether this relates to anyone having this problem, but thought I'd share anyway - just in case.
I was getting the same warning, so raised it at the first service - when I picked up my bike, the tech told me he replaced the fob battery and everything was working fine, but to make sure I didn't leave the fob close to the bike when it's not being used.
Clearly, you carry the fob when you're riding - not an issue.
His comment related to leaving the fob in a bag on the bike, or close by in your garage.
His reasoning was, the loop and the fob "poll" eachother regularly (don't know how often). Apparently, and it makes sense, they don't do this when the bike's running. BUT, when not being ridden, if they're within radiowave reach of eachother, the battery in the fob will drain.
No problem since.