pressure plates/banners "water log issue"

Some reminders:
1. This is a duplicate of "MC-125351 - Some blocks still show air around them when surrounded by water/cannot be waterlogged". Please search more generally because sometimes bugs can be present in many similar cases, and that bugs which have the same cause are usually included in a single report.
2. Please make your summary more exact. For this issue maybe "Pressure plates and banners cannot be waterlogged" is better. We can see your problem clearer if you use this kind of summary.
3. "Environment" is only for inputing your operating system/Java version, etc. If you want to attach a screenshot, simply attach it in the attachments.