issues getting dreampi 1.8 (and 1.7) to boot

[pizzapoindexter]

hey yall, looking to get my dreampi setup after finally getting ahold of a pi. for whatever reason though, it looks like the img i got from dreamcastlive.net (1.8 DLE) isnt booting, or at least isnt giving me a display on a monitor ive got connected. tried using both win32 disk imager and the official raspberry pi imager. ive also tried flashing the raspberry pi os to the same card, and it seemed to boot fine, so i dont necessarily think its the pi or sd card. wasnt able to find any documented compatibility issues with sd cards, but thats the only issue i can think of happening? i dont currently have another free sd card to try and wouldnt mind ordering one for this, but id like to try and use this one since ive got it just laying around already. im currently using the following setup:

raspberry pi 3b+
samsung 256gb evo select sd
Conexant RD02-D400 56kb modem (purchased from dreamcast live ~1.5 years ago) [EDIT: windows shows this as: conexant usb cx93010 acf modem, but the model number on the tag attached to it says RD01-D400]
dreampi 1.8 dle from dreamcastlive.net/downloads

ive also verified that the hdmi and monitor im connecting to work fine and seemed to work with the pi when i booted the base raspberry pi os.

checksums on img:
md5: 872f9fe38dc2eb12521fb1e9f2916678
sha256: 17495060465f62e04c4493e2c37a2b91d27507096357a3fad5f4b197117cdbae

not sure if anyone has run into any of these issues or knows of anything incompatible with this setup that can help out, but im eager to get it going

edit 10/16: went ahead and grabbed a sandisk ultra 64gb since i wasnt getting any responses and unfortunately no dice still. ive tried formatting the thing multiple times, using both win32 and the raspberry pi tool to image the card, and even attempting to use 1.7 all to no avail. still seems to boot totally fine using raspberry pi os, and im beginning to be at my wit's end figuring this out i really dont want to give this up but im getting really frustrated that nothing seems to work

[pizzapoindexter]

also, i forgot to add that on the pi itself im seeing a solid red light and occasionally flashing green light, so looks like its powered and reading the sd fine, just not receiving any kinda indication of it booting on the monitor. modem lights dont turn on either