Hi Athena,
thank you for your feeback. I reactivated my old WIFI router. It is a Linksys/Cisco WAG54G2. The problem is not reproduceable using the Linksys-Router. Everything works stable even if I set the modul to mode 1 using
AT+CWMODE=1
I'm testing on
AT+GMR
AT version:0.22.b1.0
SDK version:0.9.6(b1)
If I switch back to the Apple Airport Express the problem is back. If I reboot the module while it is set to mode 1 the ping will stop after a while. Regardless if I use AT+RST or HW-Reset or powercycle. The module then needs to be reset to ping again but it will again stop after a short period of time. So the problem seems to be related to the Airport Express.
The workaround I posted for nodemcu also works on AT firmware. If I set the mode to 3 before reverting it to 1 the module established a stable connection most of the time. As the firmware seems to save the connection settings you need to be fast switching after reboot as it seems not to work any more after the problem occured.
I also tried the nodemcu dev096 branch from github. With the same results as described above.
Can I do any testing or provide any information to track down the problem with the Airport Express? It would be great to use all my ESP modules with no workaround on my Airport Express