Whenever i select the option to stick to the right, the buttons disappear. Never had that problem before the update. Current fix is to set it to default (Item placement: Scrollable Main Container) and put a lot of spacing in between icons to mimic the same function.
Macbook Pro 2017 Touch Bar, MacOS 10.13.6
Unfortunately I'm unable to reproduce this. Could you go to the about tab in BTT and click the export debug information button while this is happening? This will create a folder called BetterTouchToolDebug - would be great if you could send that to firstname.lastname@example.org and reference this issue.
Ah I think I found the issue. Should be fixed in v2.603