I think this could be Sarcoscypha coccinea (or austriaca), but it's difficult to be confident with no experience and few spores to observe. Any feedback appreciated.

No spores ejected after several hours in a damp container, and I couldn't find many mature and vital asci or spores in two sections. I tried to use Spooner's key to Sarcoscypha and Sarcosomataceae in Britain (2002).

Habitat: Buried deciduous twig, muddy area with leaf litter, grass around, near Salix and Alnus, streams nearby flooding area in heavy rain.

Key characters: Hairs sinuous but not convoluted, paraphyses not moniliform below (one maybe), spores narrower and more rounded at the poles.

Vital spores measured in asci (some seem too narrow to be fully mature):
(17.1) 20.4 - 21.4 (21.8) × (7.8) 7.84 - 9.4 (11.6) µm, Q = (1.9) 2.2 - 2.5 (2.7), N = 7, Me = 20.5 × 9 µm ; Qe = 2.3.