It seems Lansweeper scans by IP rather than name. Is there a configuration change anywhere to make it scan by name? Some of our PCs aren't seen for a while because they're hibernated. Now, I can ping a computer by name and see it's IP has changed but Lansweeper doesn't know about the IP change. Therefore, if I start a server side scan it tries to use the IP it last had for it and fails.
When Lansweeper scans an IP range it scans all IP's in that IP range. As long as your asset's IP is still within the IP range of the IP range scanning target it should be rescanned and the IP should be corrected on the asset's page.
Alternatively, you could use a different scanning target like Asset group, Asset type or Windows Computer to scan based on asset name.