You need to let it cure longer.
Usually, through the first two weeks of curing, you burp your jars twice each day. Then, you burp once a day during the next two weeks.
Trying to cure with silica packs doesn't really work. So, I suggest you add another two weeks of cure for those nugs.
Also, when you burp, take the buds out of the jar and let them sit for 15-20 minutes before you put them back in the jar. I have found it really helps with the cure process.
I hope this helps.