Hive Explorer: Unknown type: "requiresScopes__Scope"

[JLambertNowNZ]

I'm not sure if this is a bug or something I'm doing wrong, so figured I'd start with a discussion

We're in the process of trying to migrate our federated graph from Apollo to a self-hosted Hive instance. For the most part it's going well. The issue in question is when trying to access the Explorer tab in the Hive UI

The UI simply displays Oops, something went wrong. Server logging shows:

server-1          | {"level":40,"time":1736459090254,"pid":7,"hostname":"60318241ee2e","msg":"Composite schema SDL contains supergraph spec, transforming to public schema (versionId: 8b8ccd71-7cb9-49fc-8095-cbfe89faa70b) - (requestId=8yVu9hLtQUOGtkdzXJj/PQ/0000000066)"}
server-1          | {"level":20,"time":1736459090363,"pid":7,"hostname":"60318241ee2e","msg":"Transformation did not change the original SDL - (requestId=8yVu9hLtQUOGtkdzXJj/PQ/0000000066)"}
server-1          | Error: Unknown type: "requiresScopes__Scope".
server-1          |     at getNamedType9 (file:///usr/src/app/@hive/server/index.js:15978:17)
server-1          |     at getWrappedType (file:///usr/src/app/@hive/server/index.js:15990:16)
server-1          |     at getWrappedType (file:///usr/src/app/@hive/server/index.js:15988:49)
server-1          |     at getWrappedType (file:///usr/src/app/@hive/server/index.js:15985:46)
server-1          |     at getWrappedType (file:///usr/src/app/@hive/server/index.js:15988:49)
server-1          |     at getWrappedType (file:///usr/src/app/@hive/server/index.js:15985:46)
server-1          |     at getWrappedType (file:///usr/src/app/@hive/server/index.js:15988:49)
server-1          |     at buildArgumentMap (file:///usr/src/app/@hive/server/index.js:16039:24)
server-1          |     at buildDirective (file:///usr/src/app/@hive/server/index.js:16001:17)
server-1          |     at Array.map (<anonymous>)
server-1          |     at extendSchemaImpl (file:///usr/src/app/@hive/server/index.js:15792:28)
server-1          |     at buildASTSchema (file:///usr/src/app/@hive/server/index.js:16264:57)
server-1          |     at file:///usr/src/app/@hive/server/index.js:319701:48
server-1          |     at file:///usr/src/app/@hive/server/index.js:308549:24
server-1          |     at NoopContextManager2.with (file:///usr/src/app/@hive/server/index.js:112089:24)
server-1          |     at ContextAPI2.with (file:///usr/src/app/@hive/server/index.js:112169:55) {
server-1          |   locations: [ { line: 29, column: 7 } ],
server-1          |   path: [ 'target', 'latestValidSchemaVersion', 'explorer' ]
server-1          | }

The SDL being parsed prior to this error includes the requiresScopes directive, but doesn't include requiresScopes__Scope scalar

Any light can be shed on this?