@DMBritos yep! it happened on wifi. I am working from home and I had to wire my laptop. My wifi signal (2.4 and 5Ghz) was dropping completely but the wired devices had no problems.

@Sevi I've had issues with this router as well. But think I found a solution. Try turning off QoS.

This could be why so many people on this thread had their issues fixed once they reset and  not used  the Tether App. Give this  a try and let me know if it works.

Qos seems to be completely broken if on for gaming and someone is streaming u will have constant 200-500ms ping spikes

worse is turning off qos defeats the purpose of qos.

it sucks having to no longer support tplink and buy a new ax router instead from asus (tuf line coming out soon).

please tplink fix qos and stop ignoring high priority clients in qos and favoring low priority clients. That isnt qos

@DanielGB I opened a specific thread, because in my case firmware downgrade did not help:

https://community.tp-link.com/us/home/forum/topic/208552?page=1

I am very very sad, I loved all the TP-Link products that I bought in the past, and this unit looks like a big promise but Firmwares seems to contain many many bugs.
In the future I will avoid to buy any recently launched routers using the first hardware and firmware versions.

@DMBritos I am disappointed too. probably this AX50 will be my last tplink product.

I am playing with QoS and the "High Priority" switch per Device Tether's features over the firmware "1.0.6 Build 20200121 rel.54912(5553)" and everytime I activate/deactivate the "High Priority" switch per Device, the router restarts... 
I will upgrade to "1.0.8 Build 20200426 rel.65338(5553)" just for testing purposes, I am decided to get rid off of this device...

EDIT (after upgraded):

Router restarting occurs if you BEFORE change the QoS profile (tested switching from "Standard" to "Browsing" and viceversa) and then activate/deactivate the "High Priority" switch on any Device. 

It restarts after saving changes , but the qos doesnt work well. ... streaming on tv set to gaming qos and preferring high priority on gaming pc still gives preference to the tv... its a crapshoot

moving on to asus ax gaming routers ($200+ range), done with these 1600 and 3000 dual band routers

@oroechimaru, I know that QoS implementation fails, but restarting just for changing the priority over an individual device is clearly a bug, it does not happen until you before change the QoS profile. Changing the QoS profile does not require a reboot neither. I confirm it is a bug because before activating QoS I played with the priority slider to see the effect on dslreports speed tests and the router continued working without the need of a reboot. Another thing to confirm my assumptions is the fact that the application does not advertise about a reboot after changing the "High Priority" slider...

@my-tplogin 

How do you turn off QoS? It is enabled by default and there are no options to remove it.

@ShaunJR i.e. after a Factory reset, if you don't use the Tether app or using it but NOT setting up the maximun upload/download speed it is deactivated in my opinion. That is the reason why in this thread many people refused to use the Tether App after a Factory Reset to solve their issues. But that is not my case, using the Tether app gets worse all, but anyway the router behaves very very strange accesing some sites/services.

Please read the entire thread to better understand.

EDIT:
Today I returned the product, I am very dissapointed about TP-Link, I am planning to buy an "USB 3.0 to Ethernet adapter" and I don't know if I should trust in any TP-Link's option...