It sound like you have a fairly new PC, so I would expect UEFI not Legacy BIOS setup. But you should go into your BIOS and check yourself.
Whilst in BIOS, also check that TPM2 is disabled.
If you have your boot stick available. Boot the USB stick and look for "Boot Repair Disk" app which should be included in the distribution.
Try running that and see if it helps.
Otherwise run Gparted and post as screenshot of the partitions on your SSD.
Note: Some basic pre-installation advice can be found here: Before you install