Error with ember-engines

Ember-cli: 3.8.1
Ember Engines: 0.6.3
Fastboot: 2.0.4

After run `ember s` and visit `localhost:4200` I have this error on my console, but the app don't crash

reproduced issue - https://github.com/villander/ember-engines.com/tree/update-engines

```
There was an error running your app in fastboot. More info about the error:
TypeError: parent.insertAdjacentHTML is not a function
at NodeDOMTreeConstruction.insertHTMLBefore (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:2361:1)
at NewElementBuilder.__appendHTML (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:3493:1)
at NewElementBuilder.trustedContent (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:3521:1)
at NewElementBuilder.appendDynamicHTML (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:3497:1)
at Object.APPEND_OPCODES.add.vm [as evaluate] (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:539:1)
at AppendOpcodes.evaluate (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:69:1)
at LowLevelVM.evaluateSyscall (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:3270:1)
at LowLevelVM.evaluateInner (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:3216:1)
at LowLevelVM.evaluateOuter (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:3208:1)
at VM.next (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:5263:1)
at TemplateIteratorImpl.next (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@glimmer/runtime.js:5299:1)
at RootState.render (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/glimmer.js:4525:1)
at TransactionRunner.runInTransaction (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/metal.js:541:1)
at InertRenderer._renderRoots (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/glimmer.js:4828:1)
at InertRenderer._renderRootsTransaction (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/glimmer.js:4865:1)
at InertRenderer._renderRoot (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/glimmer.js:4785:1)
at InertRenderer._appendDefinition (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/glimmer.js:4696:1)
at InertRenderer.appendOutletView (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/@ember/-internals/glimmer.js:4682:1)
at invokeWithOnError (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/backburner.js:336:1)
at Queue.flush (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/backburner.js:216:1)
at DeferredActionQueues.flush (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/backburner.js:413:1)
at Backburner._end (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/backburner.js:947:1)
at Backburner._boundAutorunEnd (/Users/villander/Projects/ember-engines.com/tmp/broccoli_merge_trees-output_path-Q9U75Reb.tmp/assets/backburner.js:616:1)
at process._tickCallback (internal/process/next_tick.js:68:7)
```