I am attempting to run a bitcoin node for the first time. I downloaded bitcoin core from the official website. I am running `bitcoind` in a Raspberry Pi 4 which has a Samsung T7 with approximately 220 GB still free (checked 2 minutes ago). I started downloading the blockchain on August 17, exactly 2 weeks ago. The first 10 or so days it was downloading about half a year of blockchain per day, and roughly constant speed. However, since the last 3-4 days this drastically slowed down, and now it downloads about one or two days of blockchain per day. At this rate, I will need like one more year to complete the initial download, instead of a few more days as with the initial download rate. There seems to be no error, it just became very slow. Is this normal?