continuously increasing CPU utilization under Raspbian GNU/Linux 9.4 (stretch)

[MrSponti]

I've several spotify-connect installations running on RPI2/3 under Rasbian Jessie without any issues. On Raspbian Stretch I detected a serious problem with the CPU allocation. After starting main.py the average CPU utilization amounts to 0.7%, which is fine. Over the day the CPU utilization of the background process increases continuously up to 100%. I can observe this behaviour on different RPI's, so it seems to me a SW issue.

Any idea how to fix this bug?

Below my system environment.

Raspberry Pi 3 Model B, 1 GB RAM (a02082)
No LSB modules are available.
Distributor ID: Raspbian
Description:    Raspbian GNU/Linux 9.4 (stretch)
Release:        9.4
Codename:       stretch
Linux iboard 4.14.50-v7+ #1122 SMP Tue Jun 19 12:26:26 BST 2018 armv7l GNU/Linux