Question DD-WRT on an american TP-Link Archer C9 v4?

[1984_C10]

I'm having a hard time trying to solve this issue, i asked on the DD WRT forums for a solution and even after a week there was no response.
Basically i want to install DD WRT on my american TP-Link Archer C9 v4, since i already have it on my secondary D-Link DIR-868L router, but every time i try to upload a custom firmware to the router, it only shows me a "upgrade failed" message on the UI.
On the DD WRT subreddit i was told to change my SSID to various strings and then try again, which unfortunately did not solve my problem.
Does anybody know a way to perhaps force it to accept the firmware upgrade?

 

[Phillip Corcoran]

This may be the reason:

https://liliputing.com/2016/03/tp-link-routers-sold-us-wont-support-dd-wrt-openwrt.html

Article is dated 2016 but very possibly just as relevant on new & recent models.

 

[1984_C10]

This may be the reason:

https://liliputing.com/2016/03/tp-link-routers-sold-us-wont-support-dd-wrt-openwrt.html

Article is dated 2016 but very possibly just as relevant on new & recent models.

That must be the reason, almost surely it is because my router is from 2017.
Guess i'll have to search for another router then, i wanted to limit my guests network download speed which unfortunately is not available on the C9 v4 with the stock firmware.