## Issue
The previous commit was over-doing the manual syncing, causing other usages like the Repost Modal to always reset to a different channel.
## Fix
Only do the manual syncing when the channel does not exist.
At this point, we could also just take `channel[0]` as the new value.
## Issue
Fixes `4544 Channel-creation in "Tip|Support" Modal shouldn't submit LBC immediately`
## Changes
`Form` seems to have already tried to stop the propagation of `onSubmit`, so I'm not sure why it was still propagated.
Fix by using the same method used in the `CommentCreate`, which is simply to check for `CHANNEL_NEW` as the current selection.
## Issue
Fixes `4621 Can't create Comments if you recently deleted a channel`
The `channel` that the parent passes in is from a persisted state. If the channel has been deleted, `<select>` will automatically resolve to another selectable value. However, `onChange` will not be called for this scenario, so we now have a mismatch.
## Changes
- Manually check if the value has been auto-resolved and report it to the parent.
- An extra `setTimeout` was needed. It seems like `onChannelChange` needs to be called after the first `useEffect` of the parent, otherwise the call has no effect.
## Issue
In the `Autoplay` case, if the `WaitUntilOnPage` has already opened the gates previously, the next video's Related will be loaded regardless of scroll position.
## Changes
Add a `lastUpdateDate` prop to `WaitUntilOnPage` to allow the parent to reset the gating state.
I don't really like the `lastUpdateDate` prop since it's purpose is not intuitive. Is there a standard way to do a "one-time trigger" from the parent?
This allows `RecommendedContent` to render the Card but with an empty list, so that the area isn't totally blank while waiting for `WaitUntilOnPage` to debounce.
There are cases where `WaitUntilOnPage` will incorrectly render, such as at the beginning if the upper components hasn't expanded to full size, so `WaitUntilOnPage` would be briefly visible.
Added a 300ms debounce to fix this, which would also improve scrolling performance a bit by doing less. Hopefully 300ms is enough for the upper components to inflate to full size.
