LemmyReddit started blocking VPN users on old.reddit.com
there is libreddit with multiple public instances, for example libreddit.lunar.icu
No clue how long it will take until they block that as well, but for now it works with VPN.
You can use a browser plugin for automatically redirecting.
Libreddit is discontinued and due to draconian API limits most instances rarely work
m-p{3}One could use one of the Lemmy instance dedicated at mirroring reddit as a workaround I suppose