I can confirm a similar issue. Sometimes the extractor is 0/10 even after waiting a few days. But, after I get in the area it starts up again - if I port out and check back on it later it will have sap. This doesn't always happen - so to me it looks like a bug. This is true for the server we run, but on my local seed this is not happening, yet. May be coincidental - but my gut tells me there is a bug here.