3 TP-Link Tapo C210 (WiFi connected to TP-Link Archer C64 AC1200)
1 TP-Link Tapo C310 (WiFi connected to TP-Link Archer C64 AC1200)
1 TP-Link Tapo C500 (WiFi connected to TP-Link Archer C64 AC1200)

2 TP-Link Archer C64 AC1200 routers (#1 and #2)

** 2 of the TP-Link Tapo C210 is WiFi on #1 TP-Link Archer C64 router as is TP-Link Tapo C500.

** 1 of the TP-Link Tapo C210 is WiFi on #2 TP-Link Archer C64 router as is TP-Link Tapo C310.

** The C500 AND C310 NEVER go offline. The 3 C210 go offline multiple times daily.

** C210's auto-reboot 6:00 AM daily, and still go offline 1-2 times a day.

QUESTIONS
Why, on the same TP-Link routers as the C210, do the C310 and C500 never go offline?

How do I fix this C210 problem?