Bitcoin core v0.19.0.1 automatically prunes. I keep loosing the blockchain. How can I stop this? Bitcoin core v0.19.0.1 automatically prunes. I keep loosing the blockchain. How can I stop this?

I went into preferences and I de-selected the pruning. I also added the line prune=0 to bitcoin.conf. And in spite of all that when I booted my computer after a power outage Bitcoin Core desktop pruned my copy of the blockchain. At first when I booted my Mac Bitcoin Core showed me a screen asking me for the filesystem location for Bitcoin. I had to mount the USB external disk and enter its encryption password. As soon as I confirmed the file location it took it upon itself to prune. This problem is not limited to power outages. When I upgrade to the next version of the software it prunes again. How can I put a stop this?
Start bitcoin-qt with the -choosedatadir option. You'll get first startup dialog again. Uncheck pruning there if it is checked and make sure the datadir is pointed to where you want it to point to. Once you click OK, double check the settings that pruning is disabled. Then check for a bitcoin.conf file in your datadir. If it is not there, you are fine. If it is, make sure it does not have have a prune= line.

Bitcoin Core does not prune by default, but recent changes to the Choose a Data Directory dialog may automatically enable pruning.