Chipset is the least relevant part in Tualatin support - you can run a Tualatin on an i440BX (which blatantly doesn't support it) so long as you get the right pinout (FC-PGA2 - if not you need a pin mod), the right voltage (Tualatins like 1.45V) and preferably some form of BIOS support.

Now, does this board support FC-PGA2? A clear indication is whether it supports PPGA Celerons, as PPGA and FC-PGA2 are mutually exclusive. Both that upgrade site and the manual (which I found here: https://www.driverguide.com/driver/detail.php … riverid=1552333) state support for all the old Mendocino PPGA Celerons. Also, that dodgy CPU Upgrade site just lists all the CPUs at a particular clock speed, regardless of core. There was a (rather ill-fated) Coppermine P3 1133MHz CPU. I strongly suspect that when this board claims to support 1133MHz, that's the only one it will, and not the Tualatin P3 1133MHz which needs a different socket and voltage.

If it did support Tualatin CPUs, it would also list the higher speeds (P3 and Celeron), which it does not. So I don't trust that site as far as I can throw it, and suspect you just bought an incompatible pair - at least incompatible so long as you don't get down to some serious modding...