I can create folders and copy files into the data partition on my Inspiron laptop AMD Ryzen 5 and MSi NVMe

10% of the time

As for the rest of the time, I can only view the files stored

I cannot make new folders or copy files into that partition

It looks like this

[ Mint 21.3 ][ win 10 ][ Data Partition ]

win 10 can let me write files into the partition every time, 100% of the time

I tried shutting windows 10 down properly with the "Shut Down" option but it still only lets me fully control my data partition, 10% of the time

It is very strange because, for roughly 10% of the time, it does let me fully control the data partition

Yes I have the root previledges

Windows default shutdown mode is actually a hybrid shutdown which might leave the data partition in an unclean state. If the data partition is in an unclean state then linux will mount it as read only. If you completely shutdown Windows then linux should always mount the partition as r/w.