Inconsistently alpha of first object doesn't fade in transition

## What did you do?

Simple transition between two view controllers, with one object with the same heroID.

## What did you expect to happen?

Consistent smooth transitioning

## What happened instead?

1 out of 4 transitions doesn't work well (supposedly randomly) as the first view's alpha stays 1.0 until the very last frame of the transition, instead of decreasing to 0.

## General Information

* Hero Version:
1.6

* iOS Version(s):
14.4

* Swift Version:
5.0

* Devices/Simulators:
Any device

* Reproducible in Examples? (Yes/No):
Yes

## Demo Project
n/a yet