How to reproduce:
# Create a new VFX (reproduced in URP and HDRP)
# Select it in Project Browser
# In opened Asset Inspector change Instancing Mode from Automatic Batch Capacity to Custom Batch Capacity
# Observe Editor doing this ->   !https://media.giphy.com/media/26n6XC8EYdrzRniWQ/giphy.gif|width=153,height=86!

Notes: Reproduced on macOS M1

Callstack - 

#0 0x00000103da6808 in VFXBatch::AddInstance()

#1 0x00000103da070c in VFXBatchedEffect::AddInstance(VFXBatchedEffect::BatchInstanceDesc const&)

#2 0x00000103dcba04 in VisualEffect::CreateData()

#3 0x00000103dcb4a4 in VisualEffect::OnVisualEffectAssetChanged(VFXAssetNotifyReasonFlag)

#4 0x00000103db5c0c in VFXManager::NotifyModifyVisualEffect(VisualEffectAsset*, VFXAssetNotifyReasonFlag)

#5 0x0000010360c820 in AwakeFromLoadQueue::InvokeAwakeFromLoad(AwakeFromLoadQueue::Item*, unsigned int, AwakeFromLoadMode)

#6 0x0000010360c5a8 in AwakeFromLoadQueue::AwakeFromLoadAllQueues(AwakeFromLoadMode, bool)

#7 0x000001045ea450 in SerializedObject::ApplyModifiedPropertiesWithoutUndo()

#8 0x00000102c671d8 in SerializedObject_CUSTOM_ApplyModifiedProperties(void*)