Nope that need not be it.

I had my bridge relay running for many moths with a few Mbps BW and it steadily had the guard flag set.

When doing the latest TOR upgrade I upped the BW-limit 100% but since that tor service restart it has now been running some 40 days without getting the guard flag back - despite being very stable and having double the BW it had earlier.

-------- Original Message --------
Subject: Re: [tor-relays] Relay not receiving Guard flag
Local Time: March 3, 2017 11:05 PM
UTC Time: March 3, 2017 11:05 PM
From: tor@anondroid.com
To: tor-relays@lists.torproject.org
Norris Thomlinson <norris@aktivix.org>

> Not enough bandwidth for a guard as far as i can tell.

That's my thought as well. Quoting Roger from a recent thread (from here: https://lists.torproject.org/pipermail/tor-relays/2016-December/011519.html):

"You need to get in the top 25% of the relays by speed. "Speed" in this case refers to consensus weights for recent enough authorities, or the number advertised in your relay descriptor for older authorities. Right now that varies by authority but it's in the 4 million to 7 million range."

But, no worries, I think your relay will still be useful as a fast middle node in an under-represented region. Thanks for running a relay!