PiHole seems to be loading slow

The only setting I recommend to tweak on a Pi 1B is the "memory split":

https://www.raspberrypi.com/news/new-sd-card-image/

https://www.raspberrypi.com/documentation/computers/configuration.html#memory-split-nonint

On below link, scroll down to "Steal some memory from the GPU" to see how I've done that for the Bookworm release:

Not sure if anything has changed with the Trixie release though!

Before tweaking:

$ vcgencmd get_mem gpu; vcgencmd get_mem arm
gpu=64M
arm=192M

After tweaking and rebooting:

$ vcgencmd get_mem gpu; vcgencmd get_mem arm
gpu=16M
arm=240M