I have some sort of palm plant that lives indoors. Over the couple of days or so these white spots, mostly tiny rice-shaped dots, have appeared on it. It's been losing some leaves over the last weeks. The white spots are almost entirely on the top of the leaf, rather than the underside. I can't tell if it's: scales, mealybug, white spider mites, or greenhouse white fly? Some spots are more round and look like they could be scales, but most are these groupings of the rice-shaped white blobs, some of which look a little fuzzy. No webs. They don't seem to be moving about from what I can tell.
I am by no means a plant expert and am not sure what to do. I see them along the trunk and stem. I've isolated the plant on the balcony for now. I live in Germany, if that's any help, and the plant was bought in a Home Depot type store months ago. Photos attached. Thanks in advance!