wireless traffic poor performance on 50e

Hello, I have a FWF 50e at home and configured the 2.4Ghz band for wifi. Unfortunately, the loading of webpages, watching youtube movies or even opening the App store on my phone or ipad results in really slow performance and timeouts.

When I run a packet sniffer, I see traffic flowing, but not that 'fast' as when I sniff traffic on my wired pc and connecting to the same websites. The wireless connection on my phone is excellent (actually I am testing in the same room as the AP) and I also disabled UTM for the wireless policies to see if that makes sense, but it doesn't help.

I also tried the 5Ghz band, which is less busy, but still crappy wireless connection.

Anybody an idea what goes wrong?

Regards,

Ralph