Docs TOC technical difficulty

There's something off with the docs TOC when the expanded topic is a long one - the subtopics stop displaying after a certain number. This occurs in both Firefox and Chrome (btw are we smartphone compatible?) ... This problem is revealed by comparing the TOC topics (such as "Peers" below, to the parallel topics at the top of the topic page, e.g. --

https://hyperledger-fabric.readthedocs.io/en/release-2.4/key_concepts.html

(p.s. when this gets resolved we should add a "gateway service" key concept link.)