@BigFlex 

Well, to tell you the truth, I think they are WORTHLESS!!!

OK, let me back up some. I have  an A20 V1 as well. I have NEVER found anything USEFUL in the logs... that said, it isn't only TP-Link. I replace a Netgear R8000 (for a few reasons, mostly have to do with Netgear Support and firmware, but that is another story) and the logging there, though different was useless to the average user and had MANY False Positives of attacks. I've had the A20 since Sept. 20th 2019. Never saw anything in the LOG that would remotely help me with anything about the router.

Now, log at this tidbit since we lost power and it didn't sync right when power was restored (it and the modem were on a UPS and never lost power) but the ISP head-end did and I had to power both off and on to get them sync'ed.

======================

2020-08-16 09:39:15 led-controller[1443]: <6> 288051 Start to run LAN_ON
2020-08-16 09:38:33 led-controller[1443]: <6> 288051 Start to run NIGHT
2020-08-16 09:38:33 led-controller[1443]: <6> 288051 Start to run NIGHT
2020-08-16 09:38:33 traffic-stats[5398]: <6> 269001 Clear all stats because time changed
2019-10-26 00:00:25 upnp[8537]: <6> 217504 Service start
2019-10-26 00:00:25 upnp[8537]: <6> 217505 Service stop
2019-10-26 00:00:25 remote-management[8048]: <6> 282504 Service start
2019-10-26 00:00:25 remote-management[8048]: <6> 282505 Service stop
2019-10-26 00:00:16 led-controller[1443]: <6> 288051 Start to run WAN1_ON
2019-10-26 00:00:16 led-controller[1443]: <6> 288051 Start to run WAN0_OFF
2019-10-26 00:00:16 led-controller[1443]: <6> 288051 Start to run LAN_ON
2019-10-26 00:00:15 nat[6185]: <6> 211021 IPSEC ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 L2TP ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 PPTP ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 SIP ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 RTSP ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 H323 ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 TFTP ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211021 FTP ALG enabled
2019-10-26 00:00:15 nat[6185]: <6> 211024 DMZ disabled
2019-10-26 00:00:13 nat[6185]: <6> 211501 Initialization succeeded
2019-10-26 00:00:13 nat[6185]: <6> 211501 Initialization succeeded
2019-10-26 00:00:13 led-controller[1443]: <6> 288051 Start to run WAN1_OFF
2019-10-26 00:00:13 led-controller[1443]: <6> 288051 Start to run WAN0_ON
2019-10-26 00:00:13 led-controller[1443]: <6> 288051 Start to run LAN_ON
2019-10-26 00:00:11 led-controller[1443]: <6> 288051 Start to run WAN1_OFF
2019-10-26 00:00:11 led-controller[1443]: <6> 288051 Start to run WAN0_ON
2019-10-26 00:00:11 led-controller[1443]: <6> 288051 Start to run LAN_OFF
2019-10-26 00:00:10 led-controller[1443]: <6> 288051 Start to run STATUS_ON
2019-10-26 00:00:08 led-controller[1443]: <6> 288051 Start to run GENERAL
2019-10-26 00:00:08 traffic-stats[5370]: <6> 269504 Service start
2019-10-26 00:00:08 factory-reset[5197]: <6> 284504 Service start
2019-10-26 00:00:07 remote-management[4992]: <6> 282504 Service start
2019-10-26 00:00:07 access-control[4958]: <6> 239504 Service start
2019-10-26 00:00:07 access-control[4958]: <6> 239503 Function disabled
2019-10-26 00:00:07 nat[4606]: <7> 211001 Flush conntrack
2019-10-26 00:00:07 nat[4606]: <6> 211502 Function enabled
2019-10-26 00:00:07 nat[4606]: <5> 211051 Create NAT chain succeeded
2019-10-26 00:00:07 nat[4606]: <6> 211501 Initialization succeeded
2019-10-26 00:00:06 nat[4606]: <6> 211501 Initialization succeeded
2019-10-26 00:00:06 led-controller[1443]: <6> 288051 Start to run WIFI5G_2_ON
2019-10-26 00:00:06 led-controller[1443]: <6> 288051 Start to run WIFI5G_ON
2019-10-26 00:00:06 led-controller[1443]: <6> 288051 Start to run WIFI2G_ON
2019-10-26 00:00:06 basic-security[4116]: <6> 219504 Service start
2019-10-26 00:00:06 basic-security[4116]: <5> 219606 Flush conntrack table succeeded
2019-10-26 00:00:04 firewall[2686]: <6> 209504 Service start
2019-10-26 00:00:03 imb[3475]: <6> 218507 Daemon connection succeeded
2019-10-26 00:00:03 imb[3475]: <6> 218012 ARP Binding disabled
2019-10-26 00:00:03 imb[3475]: <6> 218506 Config interface initialization succeeded
2019-10-26 00:00:03 imb[3475]: <6> 218501 Initialization succeeded
2019-10-26 00:00:03 upnp[3347]: <6> 217504 Service start
2019-10-26 00:00:03 upnp[3347]: <6> 217505 Service stop
2019-10-26 00:00:02 remote-management[2962]: <6> 282504 Service start
2019-10-26 00:00:02 remote-management[2962]: <6> 282505 Service stop
1970-01-01 00:00:08 led-controller[1443]: <6> 288051 Start to run USB1_ON
1970-01-01 00:00:07 led-controller[1443]: <6> 288051 Start to run USB1_ON
1970-01-01 00:00:07 led-controller[1443]: <6> 288504 Service start

======================

All that is the BOOT process (read from the bottom up) until 2020-08-16 09:38:33 when the actual 'connection' to the PC and the router starts the process of becoming a router. I assume the 2019-10-26 date is the day I made the last change to the Settings and saved it. Up until 2020-08-16 09:38:33 all that info would have a meaning and possibly to you if the router was failing.

Normally all I see are LED controls on/off.

NOTE: the above is from a LOG mailed to me every midnight. Quite diffferent from when you look at the router (as you did).

I also DO have Remoe Access on as I do use Thresher on my Phone to access the router when needed.

Bottom line, I've found nothing of interest to me under normal circumstances. Maybe Support could, but not me.

I think you'll only see entries from when the unit is powered on as well. The 'log' as it were is stored in RAM and that is not held by a 'flash' RAM that the settings are saved in.