Zen internet dropping every 3 minutes

Hi All! I am new to Zen and after my Fritz!Box updated to OS 7.13, my connection started being very unstable. Every 2-3 minutes I would get these entries in the Event Log:

1. Internet Connection Cleared
2. Timeout during PPP negotiation failed
3. Internet connection established successfully

After some testing I found out that when at least one ethernet port is used (doesn't matter which one), I would get the above every 2-3 minutes. Once I disconnect the cable, the connection is as stable as ever until I plug the ethernet again. This happens regardless of the device I plug in (Philips Hue, NAS, eero).

After speaking to Zen, they'll send me a loan Fritz!Box to test out however I am not hopeful that will do it. If that's the case, what modem would you recommend for a 80/20 line (ethernet only) that is also future-proof if/when I wanted to upgrade? Have any of you come across this before?


Here's my line details in case they're useful:

Negotiated Connection Properties
Receive Direction Send Direction
Max. DSLAM throughput kbit/s 80000 20000
Min. DSLAM throughput kbit/s 128 128
Attainable throughput kbit/s 80674 19624
Current throughput kbit/s 79229 19623
Seamless rate adaptation off off

Latency fast fast
Impulse Noise Protection (INP) 44 0
G.INP on off

Signal-to-noise ratio dB 3 6
Bitswap on on
Line attenuation dB 17 20
approximate line length m 402

Profile 17a
G.Vector off off

Carrier record A43 A43

Seconds With Not Remediable Errors (CRC)
Errors (ES) Many
Errors (SES) per
Minute Last
15 Minutes
FRITZ!Box 0 0 0 0
Central exchange 25 0 0.02 0

If the issue is only occurring when you use the ethernet hub on the router, it does sound like a faulty Fritz!Box to be fair. Faulty ethernet circuit could be causing lots of interference.

The other possibility is that whatever you're connecting to the Fritz via ethernet itself has an issue with its ethernet port and is pumping noise down the ethernet cable overwhelming the modem.

Speaking of ethernet cables, that could also be faulty so be sure to test with a different cable too.

Did the loan box work OK for you?

Contact AVM Support rather than Zen. Your F!B is loaded with diagnostic software. AVM are quick to respond. They will ask you to provide screenshots and diagnostic data and they will propose a way ahead. Some years ago, they replaced my faulty 4 year old 7390.