A tripwire hook connected to a line of tripwire (i.e. one that can produce a redstone signal in the presence of entities) does not allow item frames to be placed on it. If the item frame is placed before the hook is connected to anything, it pops off as soon as the hook is connected.
MC-206374
Item frames cannot be placed on active tripwire hooks
Resolved
Cannot Reproduce
0
In my testing I couldn't get item frames to attach to tripwire hooks at all, connected or not.