there is a bug with very specific extensions that cause the problem you’re describing.
thomthom selection toy is one. 1001bits tools is another. simply turn it / them off and you can customise again.
where did you read that ?
most of the sketchup staff is on mac. sketchup has massive interest in supporting mac users. so much so that they are reworking the whole UI right now to make working with pc and mac seamless.