I just bought a new sd card, reflashed it and did the IBD. The node worked fine for about 1-2 days. Now the mempool app always gets stuck (right now last block is shown 19 hours ago) At the same time the Bitcoin Node App shows the current block height as it should be. When restarting the node it sometimes only shows the empty loading UI.
I believe your pi cant keep up. its out of memory.
Get one with more RAM or cut out some of the bloat on your pi.
You can also set your mempool to flush older transactions rather than hold them for 2 weeks or even to not accept transactions of a lower value.
Blame ordinals and brc-20 for all the extra activity.
I have my mempool set to ignore anything less than 3 sat/vb. They arent being mined anyways