Hi Davoud, thanks for writing this forum entry.
Topology connection failure alerts can be something within your network or servers. The question is as well which server you had added that produces the timeouts (Backup Server / VCenter / Hyper-V Server / Cluster / VMM /...)
In general there are some knowledge base entries to increase timeouts. But I would look at the infrastructure first and fix the root cause.
Veeam ONE actual Version is 9.5 U1. When you are under maintenance you can upgrade for free to it.https://www.veeam.com/kb1649https://www.veeam.com/kb1738https://www.veeam.com/kb1643