Unable to change "Your can read only" to Read & Write on the SanDisc Info tab for my iMac running macOS Catalina 10.15.7.

Have a MAC; Late 2012; Catalina 10.15.7; Still works well; Upgraded HDD to AURA Pro SSD (that was fun); Be shame to get rid of it at this late date (me and the machine)

Problem (as we used to say in the day)/Opportunity: Have SanDisc; 250 GB; comes on line as read only (files play: B Seger & Jimmy B); Existing format appears as HFS Case-sensitive Not Journaled with Disk Utility; Unable to change "Your can read only" to Read & Write on the SanDisc Info tab - wanted to reformat to ExFAT; on info tab have control of "ignore ownership of this volume" but makes no difference. What say you folks?

[Re-Titled By Moderator]