T-ster

I have a ZDZ 80 RV which I flew for a couple of years, but it has sat for a few years since then. I flew it 3 months ago as well as today and it runs great, but noticed an odd thing. When it heats up there is play between the engine case and the prop hub. When it is cold there is no play at all, but when warm you can push or pull in and out on the prop and there is movement (maybe 1/16" or so). The prop bolts are tight, so it isn't that.

Does this mean bearings are going out, or is this ok?

Thanks.