diff --git a/src/app/FirebaseResource.ts b/src/app/FirebaseResource.ts
index 715fb6d..c867cf6 100644
--- a/src/app/FirebaseResource.ts
+++ b/src/app/FirebaseResource.ts
@@ -71,7 +71,16 @@ export class FirebaseResource<T extends FirebaseResourceItem> extends Iterable<T
 
     findNextId(collection: FirebaseResourceItem[]) {
         if ( !collection.length ) return 0
-        return collect<FirebaseResourceItem>(collection).max<number>('seqID') + 1
+
+        let maxSeq = -1
+        for ( const item of collection ) {
+            if ( !item ) continue
+            if ( !isNaN(item.seqID) && item.seqID > maxSeq ) {
+                maxSeq = item.seqID
+            }
+        }
+
+        return maxSeq + 1
     }
 
     /**
@@ -81,6 +90,7 @@ export class FirebaseResource<T extends FirebaseResourceItem> extends Iterable<T
     async push(item: T): Promise<T> {
         await this.ref().transaction((collection) => {
             if ( !collection ) collection = []
+            if ( typeof collection === 'object' ) collection = Object.values(collection)
             item.seqID = this.findNextId(collection)
 
             // @ts-ignore
@@ -96,7 +106,6 @@ export class FirebaseResource<T extends FirebaseResourceItem> extends Iterable<T
                 .startAt(item.seqID)
                 .limitToFirst(1)
                 .on('value', snapshot => {
-                    console.log('got push ID back', snapshot.val(), snapshot.key)
                     res()
                 })
         })
diff --git a/src/app/units/Blockchain.ts b/src/app/units/Blockchain.ts
index aa856a3..3967e2f 100644
--- a/src/app/units/Blockchain.ts
+++ b/src/app/units/Blockchain.ts
@@ -179,7 +179,6 @@ export class Blockchain extends Unit {
             const blocks: unknown = result.data?.data?.records
             if ( Array.isArray(blocks) && blocks.every(block => {
                 const match = isBlockResourceItem(block)
-                console.log(match, block)
                 return match
             }) ) {
                 return blocks.map(x => new Block(x))
@@ -353,6 +352,7 @@ export class Blockchain extends Unit {
     }
 
     public async getSubmitChain(): Promise<BlockResourceItem[]> {
+        await this.firebase.trylock('block', 'Blockchain_getSubmitChain')
         const blocks = await this.read()
         const submit = await this.attemptSubmit()
         if ( submit ) {
@@ -360,6 +360,7 @@ export class Blockchain extends Unit {
             blocks.push(submit.toItem())
         }
 
+        await this.firebase.unlock('block')
         this.refresh()
         return blocks
     }