I'm also having this exact issue on Windows 10 Bedrock. I'm trying to make a behavior pack with structure files, something I've done a bunch of times, and I get that same incompatible message. I downloaded the latest version of the vanilla behavior pack, and it still didn't work. I even tried deleting the dependencies section like the OP suggested, but that didn't work either. As far as I know nothing about behavior pack making has changed so this must be a bug.
I've been having major lag issues in my realm since at least early November. I always have block lag, and my members tell me that all sorts of random weird things happen to them. Its made this whole last month a pain..
I'm also having this exact issue on Windows 10 Bedrock. I'm trying to make a behavior pack with structure files, something I've done a bunch of times, and I get that same incompatible message. I downloaded the latest version of the vanilla behavior pack, and it still didn't work. I even tried deleting the dependencies section like the OP suggested, but that didn't work either. As far as I know nothing about behavior pack making has changed so this must be a bug.