siru You might want to take a look at "Solus live budgie environment won't boot" which involves a similar CPU/GPU combination (Core i3-1215U and Intel Iris XE graphics) of the same Intel generation. The most likely problem is that the 4.3 ISO (kernel 5.13) does not have the necessary drivers to support the i5-1235U with Intel Iris Xe Graphics.
I'm assuming that since you have been using Solus for several years that your Thinkpad is set up to run Solus (UEFI/GPT, Secure Boot disabled, and so on), but because looks like a new computer, you might want to check those settings just make sure.