6 month old separation problems

Just looking for some advice or tips on helping my 6 month old Springer Spaniel with her sudden increase in separation problems.

She's crate trained, happily takes herself to her crate for a nap after walks etc. She was sleeping through the night perfectly for months until the last couple weeks where she's been waking me up frequently but doesn't even need the toilet.

And the past couple days she just won't settle at all. We're still working on settling outside of the crate so she still has her naps in there, and is happy being in there for an hour or 2 while I go out.

At the moment she just keeps pulling the blanket off the front of the crate, and whining constantly, even if I'm just a metre away. She then just sits silently staring at me in her crate and just won't sleep.

I know she's getting older so needs less sleep but at the moment she's sleeping 10pm-7am overnight (waking up 3+ times) and not napping in the day which I know isn't enough sleep (and probably what is causing her destructive and bitey behaviour)

Any advice would be greatly appreciated and is getting very exhausting!