Let's get this clear first... The HHD's that you cannot mount are external USB or internal SATA drives? They were both mounted temporarily at /media/ancapistan/<device_name> ad you were in the process of copying files from it to your ssd right? So just reading from them... Not writing "to them" right?
Could you please post the output of these posted within CODE Tags?
Code:
lsblk --noheadings --bytes --pairs --output=ALIGNMENT,DISC-ALN,FSTYPE,FSUSE%,GROUP,KNAME,LABEL,MODE,MODEL,MOUNTPOINT,NAME,OWNER,PHY-SEC,SIZE,STATE,TYPE /dev/sd[c,d]
Is this machine a dual-boot with Windows?