1.15.2 oversized chunk?

I keep seeing this message in my console log…

Saving oversized chunk [-9, 7] (3227421 bytes} to external file ./world/region/c.-9.7.mcc

However, I know that none of the players is trying to DUPE anything, so this is not the dupe bug. I do have CHUNKMASTER loaded, but this has been running just fine for several months.

doesn’t have to be a dupe, a common issue has been entities due to mojangs ticking system, as well as accidentally by players storing way too much in a chest, go check out the actual chunk and see what’s there

How do I get to that chunk since I don’t know where that is (shouldn’t it be in X, Y, Z coords and not just 2 numbers (-9,7))?

The other strange thing is that the file in the region directory is the ONLY one that begins with “c.” while everything else begins with “r.”. What dimension/region/etc. begins with “c.”?

Chunks do have a Y coord, only an x/z
dinnerbone.com/minecraft/tools/coordinates/

the c. file is the file that vanilla uses for storing oversized chunks

So, please forgive my ignorance. This file “c.-9.7.mcc”, is that the specific chunk that has the problem?

UPDATE: If the numbers are the X/Z of the chunk, I went directly TO that chunk and found only 1 hopper filled with sugar cane, and a small chest also filled with sugar cane in the chunk (I went from the bottom of the world to the top of the overworld in spectator mode).

Would THIS cause this condition and if so, this should be normal, yes?