Players testing the new best Diablo 2: Resurrected classes to build for one particular focus at the cost of taking additional incoming damage of the same type.
However, players using a Diablo 2: Resurrected Sorceress build focused on summons have found that the charms are not affecting player pets such as hydras. A post on the Diablo Reddit says that charms appear to have no effect for these summoned pets. ThisPlaceisHell says they did some testing with the charms along with other enemy resistance debuffs, and states that neither gear nor Sunder Charms appear to benefit pet damage.
They explain that "builds that rely on the Sunder Charms affecting their pets to make them viable are still extremely reliant on Infinity or LR wands to work" and "effectively don't benefit from the charm unless you have other negative resist bonus skills active." They go on to note, however, that because the feature is still in preview, perhaps the change simply hasn't been implemented by Blizzard yet. Alternatively it could simply be an oversight or bug that will be addressed ahead of Diablo 2: Resurrected ladder season 2 on October 6.
Whatever the reason, this issue will clearly present a problem for anyone wanting to use a summon-focused build in the new 2.5 update. Hopefully the change will be implemented, as the patch notes suggest Blizzard were intending for this to be the case originally. ThisPlaceisHell and other s in the replies say they hope that the change is also applied to other gear to allow pets to more consistently benefit from damage type bonuses.
Players digging into the latest update have also uncovered hidden messages that seem to be part of a best games like Diablo for you to choose from.