Not sure what is causing: crashed with error "Unable to invoke target method in current thread. Use `BeginInvokeOnMainThread` method to prevent this error."

Creating the a custom indicator. Usually it works normally when attaching it to a single chart.

The indicator is using basic C# and List to store some data and calling cTrader APIs, pretty sure there is no threading stuff in the code.

These errors occur when using this indicator on multiple charts AND starting them simultaneously. (like when restarting cTrader and every charts load this indicator)

Restarting the indicator 1-by-1 on every chart and it works again without error. so I suspect it has to do with something that it using at the same time?

Thanks, Please let me know if anything.