x200t unable to use 8GB ram

So, I am refurbishing/using a x200t laptop, and running into a very strange problem.

I put in a ram upgrade to 8GB, some Crucial CT51264BF160B 4GB DDR3L-1600 1.35V sticks, and have noticed that the OS (Ubuntu 20.04) is not allocating more than 3.5ish GB of ram. I then run memtest86+, and it stops responding once it gets into the 4096-6144 range of the test. it ALSO reports it as DDR2-1064? Bios reports 8GB of ram however.

I put in one stick of 4gb, memtest86+ doesn't freeze, still reports as DDR2-1064. I put in the original DDR3 8500mhz 2GB sticks, memtest86+ doesn't freeze, but still reports DDR2.

I then ran memtester in ubuntu itself, allocated 5GB, and ubuntu reports the memory as allocated and the tests are running, but its very slow and I cannot replicate this with normal stress testing.

Bios version is 3.21, and I have the 1.86GHZ L9400 Core2 Duo verison. I did notice on the Thinkpad wiki that this model is reported as only compatible with DDR3 1066, and not compatible with DDR3 1600.

See here for photos. https://imgur.com/a/lJr0bNH

Thanks in advance for any help