Given is a locally finite countable connected poset which satisfies further the following property: Let $C$ be any maximal chain and $A$ be any antichain. Then $A$ is covered by both the sets $Past(x)$ and $Future(x)$ for $x$ running over $C$ and where $Past(x):=\lbrace y\mid y \leq x\rbrace$ and $Future(x):=\lbrace y \mid x \leq y\rbrace$. Questions: 1. Is the orbit of any point $x$ by an automorphism $f$ of the poset finite? 2. Is the group of automorphisms of this poset countable? 3. As a polish group, is the group of automorphisms of the poset locally compact? Thank you