I think you will find that if you search for "Dodderer" in all pending merges across WikiTree, you will find that proposed merge, but you will never find it under "Dotterer."
I have observed that the "Search by surname" function works only when the surname I am searching for is the LNAB on the profile that is/was proposed to be merged away. The search function does not see the LNAB of the profile that was proposed as a merge destination.
Since I am the member who proposed that Dotterer merge, I checked to verify that the behavior of the search isn't based on who proposed the merge. There's currently a proposed merge of Sinclair-5538 to Chappell-2493. If I search on "Chappell" I don't find the merge, but if I search on "Sinclair" I can see it.
(I deal with a large number of merge proposals between different LNABs, so I see this fairly frequently, and I've come to accept it as an annoying feature of the WikiTree merge process that I just need to live with. I guess it could come as a shock to members who don't often see merges between different LNABs.)