Tableau's Vertical and Horizontal Layout containers are designed/intended to allow you to specify how dashboard components should be positioned precisely (worksheets, titles, text components, image components etc).
Tableau creates tiled layout containers automatically when you place a component on the dashboard. In that instance, you're giving Tableau some control over placement.
Tiled containers are useful for getting started in simple scenarios, but when you wish to define placement yourself, you should eliminate the tiled layout containers (along with any other superfluous tiers of containers). To remove a container from the layout hierarchy on the left sidebar, just right-click on it.
You can use a vertical layout container to create a column with numerous components stacked in rows, all with the same widths but with the vertical layout container controlling the individual row heights. To construct sidebars in the margin or a vertical stack of components, use vertical containers. Horizontal containers function similarly.
You may either confine the container's options by fixing the height of each component in a vertical container, or you can let the container choose its own height based on the amount of data, the height of other containers, and the "fit" settings for each component. Horizontal containers function similarly.
To construct an arbitrary layering of rows and columns of components, you may nest vertical and horizontal containers.
You can construct responsive dashboards that operate properly when the dashboard alters size, modifying the fit, size, nesting, and layout hierarchy to obtain the behaviour you want if the dashboard size is set to automatic or range.
To summarise, remove the tiled containers, reduce the container hierarchy to what you want (perhaps just one vertical container in your instance), tweak the fixed sizes, fit, dashboard size selections, test, and you should have a functional dashboard.
It's sometimes useful to have a fake component (blank, text, or picture) that you can use to temporarily use until you have your containers set up the way you want them to be - then replace the dummy components with your genuine worksheets.