python & speedtest.py apparantly kill LE9.2.5 @ RPi4

I have added speedtest.py and it appears all hell broke loose. I use it at LE7 for many years perfectly fine. First, I copied speedtest.py from RPi2. Then I did:

To test ssh and:

curl -s https://raw.githubusercontent.com/sivel/speedtest-cli/master/speedtest.py | python -

It tested DL speed but hung everything (entire PRi4) while doing UL speed. I tried 2 different RPi4 LE 9.2.5. MicroSD got hung, TVh LiveTV hung, streaming from my server was hung, Kodi was hung, I could not SSH (Rpi4 are connected to Giga LAN)... Green LED was on for probably minutes. Why? I do not know. After some time, it went back seemingly to normal operation.

Then I turned this RPi with TVh off and back on. It went into reboot cycle. Permanent one. Display would show something about python over LE logo and reboot entire RPi (not only Kodi). Prior to that, Rpi4 with this same card and installation worked normally for this RPi4 LE version (mostly works but with constant sound synch problems).

Could someone could verify this? This same version of speedtest.py at RPi2 with LE7 works perfectly and so at the RPi Zero with Raspbian. But, at both RPi4 with LE9 I have, quite terrible experience.

I reinstalled LE so I can not get back and provide more info. Should be quite easy to verify. Second one without TVh seemingly survived on run of speedtest.py and off/on clycle..

Months later, speedtest.py still does not work on RPi3 LE9.2.6.

Well, that is an understatement. DL test works, but when it gets to UL test, it hangs RPI4 LE9 completely and forever.

Luckily my system notices that and restarts RPi4.