My concern was the health of those blocks.
Same goes for what process is the culprit of using up your CPU, since you state that its outside FL Studio. You should be able to see that in the task manager, no?
I only somewhat experience these issues you're having by loading large ass sample files longer than 50 (ish) seconds, but my system never freaked out like that, nothing outside FL Studio is throttled to the max, etc, it just freeze for a few seconds and then it works fine afterwards, I can run a session for hours with no issue.
The samples you've shared so far worked fine here, not sure what else to ask. :/