Mine in my 2019 ram bighorn are 433Mhz as well. Im pretty sure all rams, all trims use the 433Mhz. You need to verify if they are still alive with a tpms tool, and if they are indeed alive, that they are the correct frequency and compatible IDs. You never know.. ram wheels fit chevy trucks, maybe someone was running them on a chevy and put chevy tpms valve-stems in there! Ive been down this road and they only way to properly troubleshoot is using a dedicated TPMS tool to verify what you have going on. Wish you were local I would run a scan on it with my tool. Any tire shop can handle this as well.