Hi!
I am very sorry for your loss. How soon after have you introduced a new friend? Has your boy had enough time to grieve? After a very close bond, like after a deep love, it can take time to open for the new.
Looking After A Bereaved Guinea Pig
Please take the time to rad this extensive and comprehensive guide here.
Please be aware that guinea pigs are very much like humans when it comes to liking each other - if you are stuck in an office with somebody, you do not inevitably become best of friends and get on with everybody, do you?
When you boar date a bereaved piggy at a good rescue under expert supervision, it takes on average 1-3 meetings to find 'Mr Right' - key to any successful bond is character compatibility and mutual liking, and that is something that neither shops or you can predict without allowing the piggy to choose.
Unfortunately, if your boys don't click, there is nothing you can do because you cannot change a personality but keep them as alongside companions with interaction through the bars.
The options after a fall-out in this guide are the same as for a failed bonding:
Boars: Teenage, Bullying, Fighting, Fall-outs And What Next?