The board definitions do not support any sample that needs the dfu feature currently, nrf54L15_partition.dtsi needs to be adjusted to fit the memory only on the SOC.
The version that exists in my repository right now maps memory that does not exist. I should have a fix out today. Seeed should have an official fix soon too, from what I’ve heard from that team.
It’s trying to allocate enough space to do OTA updates.