Sorry for the delay, I was waiting to see if the last changes make an effect, and it does.
Update:
- I’ve upgraded the DO droplet to
16 GB Memory / 60 GB Disk / LON1 - Ubuntu Discourse on 14.04 - Change rebake to 1
- Increased workers from 5 to 8 following your suggestion in another post
10 hours later 
Now, I’ve updated the rebake to 10 and let’s see. I want to rebake all as before the crisis and then back to my previous droplet.
I think now is under control so thank you so much, everyone, for your time and suggestions, it has put me in the right way, and I learned a little bit more about how to manage this cases with Discourse.