This may or may not fix the issue for you, but the Electron installer was updated for version 1.7.4, so you have an inherent mismatch in your configuration.
Electron can be updated by downloading the full installer package from the Obsidian website:
Sorry, I got it mixed up. It seems the previous fix was for the panning issue. So, this should be a bug rather than a help request? After opening the canvas, the performance of normal markdown editing also drops to the same level as the canvas.
Not sure if related - but while trying to figure canvas performance issues, I noticed that simply opening a canvas will cause changes in the canvas file.
I use git and constantly seeing changes in canvas just from opening, which doesn’t make any sense.