Fat Great Tit, is it unwell?

We have a resident and very rotund Great Tit that has arrived in our garden over the weekend, we already have a large number of regular Great Tits, Coal Tits and Blue Tits who frequent our garden on a constant basis.

This guy is visiting our feeder but is so much slower and prefers to simply perch, it sits for hours on our decking with its wings slightly fanned and is drinking lots of water too, it is also worryingly unafraid of me and has made no attempt to fly away when approached.

Could it be unwell? I can’t see any particular signs of injuries and it does fly but clearly prefers not to. Surely it is far too late in the year to be ready to lay eggs? Also we recently had very strong winds, could its nest be damaged?

Thanks