I'd try DVD Decrypter first, then using handbrake to rip the Video_TS file.
That works about 99% of the time for me. I have a couple of DVDs at home I can't rip.
I am new to doing this on the Mac, can you post a link the "DVD decrypter" program you mention. Google reports a ton of these and I am not sure which one it is.
Handbrake/MakeMKV are failing for me in a number of DVDs.
In the Windows world I never had a problem with AnyDVD. Wondering if someone can recommend and alternative, even if it's not free.