Space after `:::` in spoiler

It seems that the web UI treats spoilers without a space after ::: the same as the regular ones, while Thunder ignores those as spoilers. It looks like the closing spoiler marker may be entered without whitespace but it consumes extra text after the spoiler, and overall acts weird

I can create an issue if that's needed, or this post may be referenced in an existing issue to be used as a test

:::spoiler no whitespace

Content

:::

::: spoiler whitespace present

Content

:::

:::spoiler one-liner no whitespace
Content:::

::: spoiler one-liner whitespace present 
Content:::

Extra text in the end

::: spoiler one-liner whitespace present 
Content
:::

Second extra text

produces

:::spoiler no whitespace

Content

:::

::: spoiler whitespace present

Content

:::

:::spoiler one-liner no whitespace Content:::

::: spoiler one-liner whitespace present Content:::

Extra text in the end

::: spoiler one-liner whitespace present Content :::

Second extra text