If you place arrows on any location of a slime block, bound only to one side by a sticky piston, the following will occur:
Arrow velocities are tightly bound to the direction of the slime block's movement, regardless of what velocity the arrow was prior.
-Arrows stuck to the bottom of a slime block, then the following slime block placed in any XZ axis movement will cause the arrow to propel in the direction of movement, rather than sticking to the slime block.
Cleaning up old tickets: This ticket has not been updated recently so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.
Also, we'd recommend making use of the search feature before writing a new bug report, as it's very likely that the issue has been mentioned already, and you can add a vote and any new information to the main ticket.
For any queries with your account or billing, you will need to contact Mojang Customer Support directly.
For feature requests or feedback, please head over to the Minecraft Feedback Site where you can search and vote for existing topics, or add a new thread if necessary.
Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki