Lawn is not growing in certain areas
Hello, I have come across an issue with my lawn and struggling to identify what the issue is. I laid a new lawn a few years back and it seemed to have established well and was looking in good condition. I am by no means an expert gardener and just wanted a smart regular family lawn! Recently certain areas of the lawn hardly seem to grow at all compared to the rest, with some areas thinning and becoming bald. I have tried to re-seed these areas multiple times with no success. I have successfully re-seeded other areas where healthier grass is growing and that has taken nicely. The grass is not over walked on and I water it regularly, feeding periodically as instructed. Never had an issue before, but the last few months indicate that something has gone wrong somewhere as new grass seeds are not taking at all. I did use some after cut weed and feed pellet things a few months back for the first and only time… not sure if this has altered the soil somehow? So, I am left scratching my head wondering if it is a PH issue, a disease or an animal/bug of some kind! I have attached some pictures of my lawn which show the effected areas compared to other healthier areas, just to see if anyone else has had this issue and could offer some advice on what to do to tackle the issue!