Model : WR841N

Hardware Version : WR841N v8 00000000

Firmware Version : 3.13.18 Build 120522 Rel. 31564n

ISP :

I am using an HP 4380 Wi-Fi printer wirelessly connected to a WR841N router.
When I try to print, if my laptop is also wirelessly connected to the WR841N everything goes fine.
If, after having the laptop connected wirelessly to the WR841N, I change the location of the laptop so that it joins another AP (I have 4 Router/Switch/AP at my place, all connected by Ethernet links to the Internet router), printing is not possible and the printer is shown as disconnected, until I disconnect the laptop for some minutes or I move it far enough from the WR841N that the Wi-Fi link is too weak.
If, when starting the laptop, after being off for a while, it connects to a different AP, printing goes fine.

The laptop uses periodic SNMP queries to contact the printer (check the printer status).
If the laptop and the printer are both connected to the WR841N Wi-Fi network the laptop issues the SNMP queries and receives the replies.
If the laptop is connected to a different AP, the SNMP queries reach the WR841N through one of the ports of its ethernet switch and the laptop receives the replies.
If both the laptop and the printer are connected to the WR841N Wi-Fi network, with the printer ok, if I move the laptop to a different location in the house, that makes the laptop change the Wi-Fi connection to a different AP, but staying in range of the WR841N, the laptop continues to issue SNMP requests but receives no replies. The situation recovers if I put the laptop to sleep for a few minutes even if when it resumes it connects to the same AP (not the WR841N) or if I take the laptop to a location where the Wi-Fi link is too weak (-90 dbm for example).
It seems that the WR841N needs some particular situations to "forget" the laptop after it moves to a different AP.
Any hints on how to solve this question?

Note:
This thread was by mistake started in a different forum and is being restarted in the right one.