In my Win 10 I have three Oracle clients.
I did connect to the database (three different schemas) with "Connect Using: client2"
After some time I did "Test All connections (Reconnect)" and Toad reconnect using client1 instead of previously selected client2.
BTW I need to reconnect after some time of not using Toad as my databases/network are configured to disconnect/drop connection.
I saw this in Toad beta 126.96.36.1996 but don't know whether this problem exists in other versions.
I don't know how this is possible. How do you know which client Toad used to do the reconnect?
I found client in two ways:
Older Oracle 19 client raises very often error "ORA-12637: Packet receive failed" when connecting/reconeccting then when I did reconnect and got this error then I was nearly sure that old Oracle is in use - it means other Oracle client than I selected for initial connection.
When Toad is connected to the database then I open Session/New connection then I saw "old" Oracle client (is gray out) - which is different that this one which I select for initial connection.
I had similar problems when swap from the troublesome 188.8.131.52 client to 19.3. Mine was that the connection list kept reverting back to 12 client, when I had swapped it over to the 19. As my 12 had almost driven John to tears, I cheated and hacked the connections.xml.