I found this particular bit at the end of The Last Jedi pretty confusing. I've only seen the movie twice so my recollection may be off, but as far as I can remember:
What's left of the Resistance decide to abandon their remaining cruiser in smaller shuttles, and head towards the old rebel base on Crait. I'm pretty sure someone mentions cloaking the shuttles so they can't be seen by the First Order (which makes sense). However, not only are they still physically visible to Admiral Holdo ("Godspeed, Rebels"), the First Order also manage to detect where they are and blast them to pieces.
Were these ships cloaked or not? If so, how could Holdo see them, and how could the First Order detect where they were? Also:
If the First Order have de-cloaking technology then what is the point of cloaking ships in the first place?