Unless it's quite recent, I was able to get the BOGO for nights 2 & 5 on Oasis August 20 sail. The booking was done on board and not pre-booked.
The funny thing was that I was cruising with family members and I had made pre-cruise reservations of Chop's +1 for them. Went to Chop's when boarded and asked the Maitre D to book my BOGO and he gives me grief by telling me that it's a party of 8 and the table was set up for 7. Mind you, this was as we boarded, and the Chop's was for the 2nd night. I looked at him and said I have 3 children and I'm sure you can squeeze another chair. Well, when we got there, it was a totally different table (by the wine refrigerator) than the one he pointed out.
Gets better, the second restaurant reserved was Giovanni's. When he entered my BOGO, he screwed it all up as he had all of us in Chop's instead of G. So instead of being Chop's and some other restaurant it was C & C.🤣
Was able to resolve it but instead of 5:30 we ate at 7:45.
I'm solo and never had any problems getting the BOGO for different nights.