Steam Overlay Transaction errors

[Cluttery]

Hi. Been using Steam since 2017, never had an issue. Since yesterday I do however. I am using the steam overlay function while playing runescape to try and renew my membership. The overlay opens fine, I put a 1month membership in the basket and proceed to checkout.

Blank page. I refresh and the checkout page shows up. I click on "use wallet funds" and I got this error:

An error was encountered while processing your request:

An unexpected error occurred while authorizing your transaction. Please try again.

So I try a couple times. Then on the third try I get this error AGAIN -but- my steam balance is now zero, rs3 tells me the sub was renewed. Everything is as it should be...even though the overlay kept giving me the error. How does that even work?

I can also no longer put money into my wallet through the in game overlay, I have to do this manually through the website. Getting this error code when I try through the client/overlay:

Something Went Wrong
We were unable to service your request. Please try again later.
E502 L3

Everything worked perfectly fine for over 7 years, heck my last transaction before trying to renew this subscription was on february 2nd 2025 and the in game overlay worked perfectly fine then. Could add specific funds to my wallet and could checkout without issues.

I am not using a VPN/Proxy, I am using the same payment method as always (paypal). Somehow the overlay broke in the past 9 days and I don't know how to fix it. Support has been contacted but perhaps someone has had these issues before and found a fix.