I have a grapefruit and satsuma that I received last summer, the grapefruit did very well putting on lots of new growth while the satsuma didn't do much of anything all year long(posted about this in a different thread).

Both plants came inside for the winter where they seemed happy, but something was very slowly eating away little holes and sections in the leaves, though I couldn't find any source of what was doing it.

But now that the weather has warmed up and the plants have been back outside for about two weeks, they're suddenly being struck with multiple issues at once.

On the grapefruit, the tops of the new growth have taken on a kind of dusty/silvery appearance with brown spots quickly spreading across the leaves.

Also on the grapefruits new growth, the stems are turning brown and woody.

On both the grapefruit and satsuma, I'm now finding these tiny little strands of web in the plants, which makes me wonder if all of this is spider mites.
Not sure if you can see the webs in the picture or not...

Any advice would be greatly appreciated. Thanks.