Above average doesn’t actually mean much - a boar pair need a cage size of 180x60cm.
When did you move them to their larger cage?
Moving them to a larger cage needed to be done but the act of moving them meant they were having a change of environment. That change of environment will cause them to go into two weeks of reestablishing their hierarchy and relationship. Sometimes that can cause underlying issues that were present (even if you hadn’t seen anything) to come to the surface and sometimes that can break a bond. You had no choice hut to change their cage size though as their previous cage was far too small.
It may not have had anything to do with that though, it may just have been an event that occurred and now their bond has broken.
They may now be a can’t live together, can’t live apart pair sadly.
It doesn’t sound like they want to be together - one sided or not. You have to be very careful not to misinterpret behaviours between the bars - not everything is friendly, ie if they lay next to each other beside the bars, that isn’t always a friendly sign and can actually just be territory marking making sure the other doesn’t cross.
Yes neutering in other countries can be very expensive but it would be the perfect solution to get back to two pairs. You could always start saving for the surgeries. If not, then your only option is to keep four single piggies.
As they aren’t neutered and haven’t been with the females, you can’t know that they will get along well though but usually a boar/sow pair is pretty stable. They still have to have compatibility though for a bond to work and the sow has to be willing to accept the boar.