Plotly Rshiny mapbox maintain zoom level when loading spatiallines

When loading lines in Mapbox via Plotly in R using a fixed zoom level via layout options, Mapbox onload zooms in to the fixed zoom level and then zooms out to show all lines on the map. Is it possible to maintain the fixed zoom level position without zooming out to show all lines?

R code plotly mapbox

output$plot ← renderPlotly({
plot_mapbox() %>%
add_sf(data = sd_all(),
type = “scattergl”, mode = “lines”,
name = ‘All lines’,
line = list(color = “#5cb85c”)) %>%
layout(mapbox = list(zoom = 20))
})