FTS crashed on an incoming node during rebalance. Panic observed: panic: runtime error: index out of range [-1]

1. Create a cluster with 1 kv, 2 fts nodes. Create magma bucket, 2 collections. Load 10k items with embeddings.
2. Start a vector search query load.
3. Do a rebalance IN of a fts node
4. Do a rebalance OUT of a fts node
5. Do a rebalance 2 IN & 1 OUT of a fts node. Fts crashed on .232 node

   KV nodes in cluster: ['172.23.107.76']

   CBAS nodes in cluster: []

   INDEX nodes in cluster: []

   FTS nodes in cluster: ['172.23.107.237', '172.23.107.126']

   QUERY nodes in cluster: []

   EVENTING nodes in cluster: []

   Servers coming in : ['172.23.107.240', '172.23.107.232'] with services: ['fts', 'fts']

   Servers going out : ['172.23.107.237']

6. Rebalance failed

   Node 232
   Service 'fts' exited with status 2. Restarting. Messages:
   /home/couchbase/jenkins/workspace/toy-unix-simple/cbft/protobuf/search.pb.go:949 +0xd0
   github.com/couchbase/cbft.serverInterceptor({0x1435000, 0xc000524170}, {0x1dea630, 0xc0006f02d0}, 0xc00627ff38, 0x19f0910)
   /home/couchbase/jenkins/workspace/toy-unix-simple/cbft/grpc_server.go:365 +0x278
   google.golang.org/grpc.(*Server).processStreamingRPC(0xc0005ba000, {0x1def060, 0xc005de4b60}, 0xc0063ac6c0, 0xc000594120, 0x27bf860, 0x0)
   /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:1675 +0x12c7
   google.golang.org/grpc.(*Server).handleStream(0xc0005ba000, {0x1def060, 0xc005de4b60}, 0xc0063ac6c0, 0x0)
   /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:1755 +0x9a6
   google.golang.org/grpc.(*Server).serveStreams.func1.1()
   /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:986 +0xbb
   created by google.golang.org/grpc.(*Server).serveStreams.func1 in goroutine 622
   /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:997 +0x145

Panic on 232:

panic: runtime error: index out of range [-1]

goroutine 623 [running]:

github.com/blevesearch/bleve/v2.distributeKNNHit(...)

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/github.com/blevesearch/bleve/v2@v2.3.11-0.20231215161722-ba3fe9904583/search_knn.go:339

github.com/blevesearch/bleve/v2.redistributeKNNPreSearchData(0xc0006f0d20, {0xc000681090, 0x1, 0xc000512000?})

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/github.com/blevesearch/bleve/v2@v2.3.11-0.20231215161722-ba3fe9904583/search_knn.go:367 +0x439

github.com/blevesearch/bleve/v2.(*indexAliasImpl).SearchInContext(0xc00626cdc0, {0x1de6f40, 0xc0065476b0}, 0xc0006f0d20)

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/github.com/blevesearch/bleve/v2@v2.3.11-0.20231215161722-ba3fe9904583/index_alias_impl.go:189 +0x49d

github.com/couchbase/cbft.(*SearchService).Search(0xc000524170, 0xc006392bd0, {0x1ded240?, 0xc0065142f0})

        /home/couchbase/jenkins/workspace/toy-unix-simple/cbft/grpc_server.go:267 +0x1364

github.com/couchbase/cbft/protobuf._SearchService_Search_Handler({0x1435000?, 0xc000524170}, {0x1de9d48, 0xc0063ae280})

        /home/couchbase/jenkins/workspace/toy-unix-simple/cbft/protobuf/search.pb.go:949 +0xd0

github.com/couchbase/cbft.serverInterceptor({0x1435000, 0xc000524170}, {0x1dea630, 0xc0006f02d0}, 0xc00627ff38, 0x19f0910)

        /home/couchbase/jenkins/workspace/toy-unix-simple/cbft/grpc_server.go:365 +0x278

google.golang.org/grpc.(*Server).processStreamingRPC(0xc0005ba000, {0x1def060, 0xc005de4b60}, 0xc0063ac6c0, 0xc000594120, 0x27bf860, 0x0)

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:1675 +0x12c7

google.golang.org/grpc.(*Server).handleStream(0xc0005ba000, {0x1def060, 0xc005de4b60}, 0xc0063ac6c0, 0x0)

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:1755 +0x9a6

google.golang.org/grpc.(*Server).serveStreams.func1.1()

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:986 +0xbb

created by google.golang.org/grpc.(*Server).serveStreams.func1 in goroutine 622

        /home/couchbase/.cbdepscache/gomodcache/pkg/mod/google.golang.org/grpc@v1.58.3/server.go:997 +0x145