Asus router here. And in almost every case that sounds genuinely identical to mine (there have been a few others in the thread that sound different – the ones which have the IP address displayed, rather than the “reconnecting” message), it seems we have set it up with fixed IP addresses on the router. The consistent behaviour seems to be that only rebooting the OpenSprinkler unit – not anything else – will resolve the problem in these cases.
It does seem that there are other potential problems with wifi connections to the OpenSprinkler – some of which appear to have been resolved by setting a fixed IP address on the router – but the one a number of us are facing with the unit being stuck on “reconnecting” until rebooted, is a distinct one, and does not appear resolved by the suggestions that have appeared here so far.
On the bright side, my unit seems to have been up for a couple of weeks without the problem occurring… but that’s also the trouble with intermittent faults.