Is this a bug or feature? On my Dlink DAP-2695 running OpenWrt 19.07.5 no communication passes in between wireless clients unless hairpin_mode is set to 1. I had to add a 10 seconds delayed script in /etc/rc.local forcing hairpin_mode to 1 on both 2.4GHz and 5GHz interfaces to compensate for this. Otherwise by default the hairpin_mode is 0 after the restart. The AP is in a gateway mode having all active interfaces bridged. Isolate Clients is off and confirmed the same in the config file.
This whole route could be just a option gateway 192.168.1.245 under lan interface.
Also 192.168.X.X are private addresses, there is no need to redact them.
Apart from the things @lleachiiasked you to clear up, post also the output of ubus call system board
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
# Revision 210109
# This is a workaround for possible bug that prevents WiFi clients to reach each other
# option multicast_to_unicast '0' does not seem to work
# sleep 10 added to allow the interfaces to start up. Otherwise the commands do not take effect.
echo 1 > /sys/devices/virtual/net/br-lan/lower_2.4GHz/brport/hairpin_mode
echo 1 > /sys/devices/virtual/net/br-lan/lower_5GHz/brport/hairpin_mode
option signal_... is currently idle as the related script has been disabled. It used to force clients to disconnect from the access point and renegotiate when the signal dropped below certain level. It made 5GHz linked clients to migrate to 2.4GHz band. As there were some unintended consequences it is parked for now. It should not interfere with anything.