UncleSlacky I was able to update everything except unrar by using Discover instead and deselecting unrar. Manually attempting to reinstall unrar via eopkg gives the same error as seen with GNOME Software:
Total size of package(s): 177.70 KB
Downloading 1 / 1
Package unrar found in repository Solus
Failed to fetch file, retrying 1 out of 5 "https://cdn.getsol.us/repo/polaris/u/unrar/unrar-7.2.5-52-1-x86_64.eopkg": HTTP Error 416: Range Not Satisfiable
Failed to fetch file, retrying 2 out of 5 "https://cdn.getsol.us/repo/polaris/u/unrar/unrar-7.2.5-52-1-x86_64.eopkg": HTTP Error 416: Range Not Satisfiable
Failed to fetch file, retrying 3 out of 5 "https://cdn.getsol.us/repo/polaris/u/unrar/unrar-7.2.5-52-1-x86_64.eopkg": HTTP Error 416: Range Not Satisfiable
Failed to fetch file, retrying 4 out of 5 "https://cdn.getsol.us/repo/polaris/u/unrar/unrar-7.2.5-52-1-x86_64.eopkg": HTTP Error 416: Range Not Satisfiable
Failed to fetch file, retrying 5 out of 5 "https://cdn.getsol.us/repo/polaris/u/unrar/unrar-7.2.5-52-1-x86_64.eopkg": HTTP Error 416: Range Not Satisfiable
Program terminated.
Hit max retry count when downloading: "https://cdn.getsol.us/repo/polaris/u/unrar/unrar-7.2.5-52-1-x86_64.eopkg"
