Refresh Token randomly is invalid

I run a little private website to have my Fortnite XP progress displayed. I am using the EpicAPI to connect to the QueryProfile which generally works very well. I automated this process to update my stats every 5 minutes using Google App Script to fetch my website. I run into the following issue though. Out of nowhere, rather than getting my auth key and refresh token extended, I get the following response:

May 22, 2023, 6:49:20 PM: {"errorCode":"errors.com.epicgames.account.auth_token.invalid_refresh_token","errorMessage":"Sorry the refresh token 'MY_REFRESH_TOKEN' is invalid","messageVars":["MY_REFRESH_TOKEN"],"numericErrorCode":18036,"originatingService":"com.epicgames.account.public","intent":"prod","error_description":"Sorry the refresh token 'MY_REFRESH_TOKEN' is invalid","error":"invalid_grant"}

I usually recieve the following (success message):

May 22, 2023, 6:44:20 PM {"access_token":"MY_TOKEN","expires_in":7200,"expires_at":"2023-05-22T11:14:20.132Z","token_type":"bearer","refresh_token":"MY_REFRESH_TOKEN","refresh_expires":28800,"refresh_expires_at":"2023-05-22T17:14:20.132Z", and so on

As you can see, these responses were only 5 minutes apart but produces these results. Is there a way of avoiding this issue? Or is there a workaround? Is there any information on this in the docs that I missed or by Epic Games?

MixV2 / EpicResearch

Refresh Token randomly is invalid #130