Seen this plenty of times for all the reasons listed above, foil edges, large grain steel breaking off, and so on. Tape helped some keeping down at 8k worked well for others. Every razor is different and as you go along you will find what THAT razor likes. Your skills will only get better as you try out new ideas

My first 2 years of shaving with a straight was off a Norton 4/8k stone, worked just fine (and far more affordable...)