Our next door neighbours have complained to the landlord about 2 things:
First about visitors parking at the end of our drive. This happened on one occasion in over a year of us living there when my Dad came to drop something off. It wasn't actually blocking their drive and Dad and DH apologised as the neighbour was clearly annoyed when she arrived home as Dad was leaving but she blanked their apology. We always make sure our visitors park up the street out of the way.
Secondly that our back garden is untidy, which it is, however only in that the grass is long and the rabbit run cover is tatty. The garden gets waterlogged when it rains so we can't mow it unless the weather is better. Also, they can only see our garden if they stand looking out of their upstairs back window so it doesn't affect them a great deal.
They also dislike the fact that we have cats although there are about 8 other cats on the street. They have never actually complained about them, but I have a feeling that might be contributing to them complaining about other stuff. We don't like their visitors who come every weekend and make it very tight for us to get out of their drive, and we certainly don't like their yappy dog which barks late at night when they let it out and whenever we are in our garden, but we accept that sometimes there are minor things you dislike about neighbours so haven't said anything because it would be petty.
We wouldn't mind if they actually talked to us if they have a problem but going straight to the landlord about minor things will reflect badly on us as tenants and we're upset because we are very happy here and want to stay long term and potentially buy the house if the LL will sell in a few years.
AWeBU to be so upset and quite annoyed too? I will be going round tomorrow to point out that they can always talk to us if they have a problem as we don't want to be on bad terms with the neighbours.