Dont know if classed as a 20 pin as one missing I just checked my MB and it has a TPM but like the picture of an other make of MB from the net 19 pin.My ASUS motherboard has a TPM slot but it is a 20-pin one and only supports 1.2 not 2.0 which is required for Windows 11.
I was always planning to build a new PC anyway when the ridiculous stock and pricing situation had settled down so I guess it is not that big of a deal to just stick with Windows 10 for now and just get a new PC with Windows 11 installed. It likely will not officially release until 2022 or even 2023 anyway.
I'm in the same boat. I built mine a bit back and and for the first time struggled after fitting the new MB even had Toko who was a genius and building computers and was off round the world sorting systems out had a job getting in to work correctly so as he's not here I lost confidence to build my own again as he sadly not with us as my back up help.
Like you I also a gamer and not had any problems with games which run fast.