Phylloscopus collybita tristis confirmation (1 Viewer)

[Marcio Cachapela]

Hi all.
I saw this Phylloscopus at 23/11/2020 near Lisbon, Portugal and then again at 27/11/2020 at the same location.
The bird was very gray above and and white on underparts through bins.
The bird shows Cold grey mantle, head, fligth feathers, white underparts, whitish supercilium and dark loral stripe.
The bill seems small and almost all dark.
First two pictures were taken under direct light and last two in shadow.
It seems that it is a good candidate to Phylloscopus tristis.

 

[Nutcracker]

Looks promising but I'd want to hear it calling to be sure

 

[Marcio Cachapela]

Looks promising but I'd want to hear it calling to be sure

Thanks for your opinion.
The original post pics were taken at 23/11/2020.
I went back to the site at 27/11/2020, and took a few more pictures but worse than the previous ones. I used the Tristis call and the bird appeared but did not vocalize.
These two photos are from 11/27/2020.

 

[Mark Lew1s]

I don't think this is tristis - not pale enough underneath, superciliium too weak, upperparts look too dark and no green tones in the wing, no warm wash to face, etc