Raster map loses most detail when zooming out

[annafn]

Hi,

I've just started using ArcGIS Pro 3.0 and have imported a project that I was working on several months ago in ArcGIS Desktop. (My university has migrated to Pro)
I'm using about 100 georeferenced tiff files downloaded from Digimap that I had no problem using as a base map previously.

However working in Pro the details of the map are completely lost upon zooming out - see attached images. This makes them pretty much unusable now, and I've already spent so much time on this project! Any help appreciated.

Thanks in advance!

(I'm on PC desktop, Windows 10)