Moving around a graph/subgraph can be very slow, e.g. dragging around or zooming in or out.
Also effects things like adjusting panel dividers, e.g. between the graph tree on the LHS and the graph on the RHS.
If the graph tree is large, then a drag or zoom operation can take several seconds to respond.
Hiding the subgraph tree, made the response time normal/fast again, e.g. by selecting the heat map instead, or by selecting the subgraph list vs tree.