What playback devices have you tried?
I am in the UK, so assuming you are a UK customer and not a Republic of Ireland customer.
When you go to the Sports main section, did you check by going to the dedicated thumbnail that says Motorsport, then click the on the F1 competition box ?
Or from the main sports screen page, go down to the very bottom of the screen where you will see a grid row of Sky Sports channel names and under the Sky Sports channel F1 box or thumbnail depending on your device click on Sky Sports F1 channel.
Both methods above worked for me on my Android phone to find the Japanese F1 full race or Japanese F1 Highlights.
From the screen shots below I found the Japanese F1 catch up from either clicking on the grid row where it says Motorsport Competitions and clicking on the F1 box.
Or the second method to reach the Japanese F1 on catch up I clicked on the bottom grid row where you see Sky Sports F1 channel.
Click on the little camera in the row of icons you see at the top when posting.
If it isn’t present, then you need to make a few more posts before you are granted access to it.
Glad you found the Japanese F1 race on catchup.
I can see where you are looking on the dedicated Motorsport screen with the previous F1 races and other motorsport content where the Japanese F1 is not there.
To be honest I rarely look at that screen page and when finding F1 content on Demand I always either go into the Sky Sports F1 channel folder right at the bottom of the main all sports screen.
Or go to the Motorsport Competition grid row and click on the F1 box.
As shown on my previous two screen shots.
The Japanese F1 was available on catch up when I posted back on the 26th of September.
Seen your post this morning and checked again and all the Japanese F1 content on catch up has been removed by NOW for some unknown reason.
If you only want to watch the F1 race and not everything from the race weekend.
Then looking at the TV Guide today, the Japanese F1 race is on a live repeat at both 11am and 5.30pm if you can watch at either of these times on the Sky Sports F1 live channel.
Also check the Sky Sports TV Guide through the week, where there maybe further live repeats on the Sky Sports F1 channel with regards to the Japanese F1 race.