Electrum-personal-server isn't seeing any historical transactions; using a Trezor I followed the instructions in the Electrum Personal Server guide. I know that the transactions are there because I checked wallet.trezor.io. But none are showing up in Electrum. I have run --rescan. I have bitcoind running in the background as a full node.

The instructions are here: https://github.com/chris-belcher/electrum-personal-server
It's the wallet type. There are three address types: legacy, p2sh-segwit and segwit. Choose the right one or your transaction history will be empty.