Edit. I just notice two beta updates ahead of the one i was on. One came in this morning. Ill retest everything. Im leaving the rest of this post in case any of my observations help. ….
I observed the same symptom this morning on my ipad. At least this morning however it wasnbetter on the apple tv, but there are two use cases - see below
On the ipadI i took a screenshot as it was happening.
Unfortunately i couldn’t submit beta feedback from the app. It is stuck and wont go to the next menu to submit anything. Is the submit feedback menu in the testflight snubbed out in the code?
However was able to sent diagnostics from the app but this was many minutes after the guide eventually loaded.
I can wait again after a long pause and submit the screenshot from the share sheet next time the guide is stuck with less delay hopefully while its in the stuck state. Now with beta update from 1/14
Also, on my apple tv, i have a different use case and i did not observe the lazy guide this morning. On my apple tv i automatically load a live station on start up. It seems that loading the station and then going to the guide helped the guide load normally this morning. So possibly there is some improvement from earlier in the week
On the ipad i set the start up settings to statically go to the guide.
Also, please note that whenever i manually shut down the app in the app switcher (both clients) , or for some reason channels forces a restart the - like after software update, whenever i see the “preparing guide message” the guide always loads just fine.
Hope this helps, and let me know if there is anything else you want me to try to duplicate the issue. .