Weird and inexplicable crashes when using TypedArrayContents

I'm getting really weird crashes with v8 array buffers / typed arrays

Base:

size_t numEntries = 2 * TOTAL_NUM_BANDS;
size_t numBytes = sizeof(float) * numEntries;
v8::Local<v8::ArrayBuffer> dataBuffer = v8::ArrayBuffer::New(v8::Isolate::GetCurrent(), numBytes);
v8::Local<v8::Float32Array> dataArr = v8::Float32Array::New(minMaxDataBuffer, 0, numEntries);

works:

 auto dataPtr = static_cast<float*>(dataBuffer->GetContents().Data());

segfaults:

auto test = Nan::TypedArrayContents<float>(dataArr);

...but it doesn't segfault immediately, but rather a couple of seconds later, probably when some GC happens.

I don't even need to do anything with the pointer. It is enough to construct a (temporary) Nan::TypedArrayContents

I have digged through the nan_typedarray_contents.h header

once I comment out

data = static_cast<char*>(buffer->GetBackingStore()->Data()) + byte_offset;

there is no crash.

I tried to find out what this is, but now it's getting really weird:

auto dataPtr2 = static_cast<float*>(dataBuffer->GetBackingStore()->Data());
//auto dataPtr3 = static_cast<float*>(dataBuffer->GetBackingStore()->Data());

works.
Where as

auto dataPtr2 = static_cast<float*>(dataBuffer->GetBackingStore()->Data());
auto dataPtr3 = static_cast<float*>(dataBuffer->GetBackingStore()->Data());

(just the first call repeated)
segfaults immediately... I suppose this is a node bug?

I'm compiling against electron 8.0.0, node version should be 12.13.0

I'll try with a later node / electron version now

Start with nan_typedarray_contents.h and the reported TypedArrayContents construction, then reproduce the crash using Electron 8.0.0 with Node 12.13.0 and the provided ArrayBuffer/Float32Array code. Compare the GetContents and GetBackingStore paths while observing the delayed and immediate failures around garbage collection. Done means the reproduction no longer crashes or the issue is narrowed to a confirmed upstream component with a focused test or report.