Git merge for conflict cases replaces local copy with the common ancestor copy

We are using free self-hosted edition of Gitlab 13.8.4-ee. When performing merging in Git, if there are conflicts for a file which are not automatically resolved, the local and remote copies of file opens in external tool (Beyond Compare) along with the common ancestor version.

If we are manually resolving one of the multiple conflicts within a file by choosing the server copy, and ‘Save’ the file in Beyond Compare, then for other conflicts in the file, the common ancestor version replaces the conflict lines in the local copy.

Is there a way to make Git replace the remaining unresolved lines within the file, with the existing local version itself?