i'm pretty sure this might be a result of the ER wiki still struggling with its transition from the older wiki format to UCP (what Fandom uses now)... as far as I know, there's two possible fixes for this, a temporary fix and a permanent fix:
or, for the easier, more permanent fix (which might take a little while longer to get implemented):
because the wiki's CSS is so outdated, so are a good majority of the infoboxes on this wiki thanks to the old code. thankfully, the new infobox format doesn't have the aforementioned issue, and whenever I finish updating the character pages, I'll start working on updating the episode pages, and not only will the impossible-to-read episode links become readable again, the appearance of the pages overall will improve!