Deleting isolated nodes in facet_edges() graphs

[SantiFilippo]

I am trying to facet my graph after bind_graph(). The two networks I am binding have different sets of edges: a first one only includes edges from a specific node, the second only includes edges directed to that node.
When I plot the graph, I obtain the two cloud with no isolates. When I use the facet_edges() option, I obtain the two clouds in distinct panes, but now they both include the unconnected nodes from the other graph.
I tried to solve the issue, but I could not find how.
My code is

`

Overall network

g.tot.1 <- tbl_graph(nodes = nodes, edges = fdi) %>%
activate(edges) %>% filter(sector == 'Financial Services') %>%
activate(nodes) %>% filter(!node_is_isolated()) %>%
activate(edges) %>% mutate(tofrom = ifelse(.N()$name[to] == 'DUB', 1, 2))

incoming edges

g.to.1 <- g.tot.1 %>%
filter(tofrom == 1) %>%
activate(nodes) %>% filter(!node_is_isolated())

outgoing edges

g.from.1 <- g.tot.1 %>%
filter(tofrom == 2) %>%
activate(nodes) %>% filter(!node_is_isolated())

Plot

g <- g.to.1 %>% bind_graphs(g.from.1) %>% activate(nodes) %>% filter(!node_is_isolated())

ggraph(g, layout = 'fr') +
facet_edges(~tofrom) +
geom_edge_link() +
geom_node_point(size = 5, colour = "steelblue") +
geom_node_text(aes(label = name), colour = 'black', vjust = 0.4) +
ggtitle('FDI From and To Dubai', subtitle = "Financial Sevices") +
theme_graph(foreground = 'steelblue')

`