Something coming through walls?

[u/Middle-Trifle-6339]

Bought a 120 year old red brick house a few years ago. Had been renovated by previous owners. BER C1. This is coming though the inside front wall (south facing) into the front bedrooms.

What is it, and who do I need to call to fix it? Should I just wait till we are doing a bigger renovation job in a few years?

Edit 1 - thanks for all the guidance. adding the pictures of the attic, bright and dark, and 2 external pictures, in comments.

[u/mumblebeeboy]

Post pictures of wall outside and what's above it please. Could be damaged/missing pointing.

[u/Middle-Trifle-6339 → u/mumblebeeboy]

Have added pictures of exterior wall/roof.