Image thumbnails not generating in replicator sets

Thumbnails are working in an assets field outside of a replicator

<img src="http://site.test/cp/assets/thumbnails/xxxxxxxx">

However, for assets fields inside of the replicator, I'm seeing broken links with this pattern:

<img src="assets/pages/filename.jpg">

Any ideas as to why this would be happening? It seems to sporadically break.