"arp_table[i].q == NULL" failed on ping

[bongo1000]

i run an ESP32 with a LAN8720 module attached.
besides other jobs, the ESP32 scans the subnet to detect if all known IP addresses are available, i.e. to detect if any server fails to respond. this is done by periodically pinging those IP addresses.

when doing so, i randomly get reboots, i.e. SW_CPU_RESET.
the interval between two such resets goes from a few minutes to a few days.
i was able to isolate the program location where the reset occurs. it most of the time happens immediately after calling the ping.
whenever a reset occurs, the message thrown to the serial terminal is always the same. see below.
i only understand that this must have something to do with the arp table, but unfortunately i do not really understand the reason for the reset and have no idea how to fix it.
please help!

assertion "arp_table.q == NULL" failed: file "/home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/lwip/lwip/src/core/ipv4/etharp.c", line 383, function: etharp_find_entry
abort() was called at PC 0x400f7c17 on core 0

ELF file SHA256: 0000000000000000

Backtrace: 0x40088808:0x3ffb3cf0 0x40088a85:0x3ffb3d10 0x400f7c17:0x3ffb3d30 0x4012fef9:0x3ffb3d60 0x401304ed:0x3ffb3d90 0x40130811:0x3ffb3db0 0x40121b56:0x3ffb3de0 0x40121b99:0x3ffb3e20 0x40121bc6:0x3ffb3e50 0x4012dbad:0x3ffb3e80 0x4012dc57:0x3ffb3eb0 0x40129516:0x3ffb3ee0 0x4012956f:0x3ffb3f00 0x4012a033:0x3ffb3f20 0x40129f21:0x3ffb3f40 0x4012a0d4:0x3ffb3f60 0x40126ad8:0x3ffb3f80 0x40089a96:0x3ffb3fb0

Rebooting...
ets Jun 8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:1044
load:0x40078000,len:10124
load:0x40080400,len:5828
entry 0x400806a8