There was an issue with construction layers, especially when their line type is not continuous.
That seems to be valid for you, if I saw it correct on the screenshot.
So the options are to switch off construction layers for zooming or update your LibreCAD version.
For Windows we have nightly builds where this issue is solved.
But the latest nightly build has some other issue with file save, so you'd better use LibreCAD-Installer-2.2.0-rc1-142-ge38b7088.exe for update.
It's a release candidate version and as stable as the version you use now.