I am new to growing hibiscuses other than the rose mallow which brings me delightful blooms year after year. I bought one this year and it seems perfectly healthy. Every morning I check, something has cut off a healthy stem. It is cut at an angle and if I didn't know better, I would think somebody is cutting it off with pruning shears. Sometimes the stem is completely off, laying on the ground, other times it is hanging on by a thread. I have looked for pests of and can't find anything.

Can anyone help?

Thanks in advance.