As I already told you, the white page does not happen in this case. The white page will only happen if there is some third party issue. Typically it's either a file not copied or a code cache issue. We try really hard to prevent a timeout issue which would lead to a hard crash of PHP and files not being copied, but that's not always feasible and depends on your host. We do try to clear the code caches, as long as the host has not blocked that feature.
Now, based on what you've said so far your issue looks like a code cache acting up WITHOUT the host giving us the option to reset it. I would also venture a guess that you had version 2.4.1 installed which is not affected by the update issue since, well, updates do seem to initiate. Why does the manual update fix your issue? I would assume that's because the filesystem cache gets wiped around that time, forcing the code cache to see the new files, fixing the "old code mixed with new code in PHP code cache memory" issue. Again, maybe ask your host to disable the code cache since you're talking about sites which clearly are not meant to get any IT support, i.e. the client will have zero clue how to reset a code cache after updating any kind of code on their site?
Nicholas K. Dionysopoulos
Lead Developer and Director
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