Spell slot markers not showing

I am level 11, Sorcerer 9, Bard 2. Here are some screenshots. It shows the diamond tick box for 6th level, but I don't even have any level 6 spells. And the diamond tick boxes are missing for all the other levels. They do not reappear if I long rest. And when I switch to slot view it's blank for everything except that 6th level, where it shows the one marker. So odd.  Any way to fix this? 

One of my Wizard players was missing his first level spell slots today. Went into Level Up then back to the sheet and they reappeared…