Well it was reported that the user itself change something:
A user has reported losing a lot of BSV because they changed the script type of their multi-signature wallet to “accumulator multi-signature”. Please stick with the default script types for all of your wallets unless you are willing to accept the risk.
https://roger-taylor.medium.com/dont-use-electrumsv-s-broken-accumulator-multi-signature-fa15147dbfa4So the fault is in the user, maybe he thinks he knows what he is doing resulting to lost of his funds. Another expensive lessons to learn in crypto sphere. Anyways, BSV never got the support from this community either, so another reason why we should stay away from them.