BT_BTC: btc_transfer_context No memory

[Sky.Soo]

W (1867354) BT_BTC: btc_transfer_context No memory
E (1867354) BT_BTC: btc_gattc_cback transfer failed
E (1867454) BT_HCI: host_recv_pkt_cb couldn't aquire memory for inbound data buffer.
assert failed: host_recv_pkt_cb hci_hal_h4.c:552 (0)

Is it memory leak?
BT controller can drop packet?
Firmware reboot is unexpected, any idea to fix it?
Thank so much!

[MicroController]

Is it memory leak?

Maybe. It surely indicates that you're out of RAM/heap. You application may be using too much or failing to free unused heap memory.