Messages similar to the following:

(o2iblnd_cb.c:3516:kiblnd_check_conns()) Timed out tx for 172.26.13.33@o2ib: 665162 seconds

indicate that sometimes tx timeout is calculated incorrectly when LND is queuing the message for transmission. 

Quick inspection of the code appears to confirm that 

kiblnd_launch_tx()

is able to bypass proper tx_deadline initialisation under certain conditions. Submitting this ticket to investigate how to fix this properly as well as better understand the effects.