Postgresql – Postgres: Performance: Slow index scan

I have a really big query, that queries data from various tables. I have tried various approaches to optimize the query.

• Made possible LEFT JOIN as LEFT LATERAL JOIN, so that the lateral join queries are computed after fetching results from the main query
• Removed GROUP BY since the aggregation took more time.

But even the final query that I had come up with is slow when I try to order it by an indexed column. Please suggest to me how I should get started on optimization.

Here is the query and the explain analyze detail
https://explain.depesz.com/s/kTBh

Here is the EXPLAIN (ANALYZE, BUFFERS) with indexscan ON:
https://explain.depesz.com/s/SyRu

Here is the EXPLAIN (ANALYZE, BUFFERS) with indexscan OFF:
https://explain.depesz.com/s/TPDv

Indexes on the tables:

CREATE INDEX idx_screens_name ON public.screens USING btree (name);
CREATE INDEX idx_screens_number ON public.screens USING btree (((data ->> 'number'::text)));
CREATE INDEX idx_screens_tags ON public.screens USING gin (tags);
CREATE INDEX idx_screens_theatre_id ON public.screens USING btree (theatre_id);

CREATE INDEX idx_theatre_companies ON public.theatres USING gin (company_ids);
CREATE INDEX idx_theatres_chain_name ON public.theatres USING btree ((((data -> 'chain'::text) ->> 'name'::text)));
CREATE INDEX idx_theatres_city_name ON public.theatres USING btree (((((data -> 'address'::text) -> 'city'::text) ->> 'name'::text)));
CREATE INDEX idx_theatres_country_name ON public.theatres USING btree (((((data -> 'address'::text) -> 'country'::text) ->> 'name'::text)));
CREATE INDEX idx_theatres_name ON public.theatres USING btree (name);
CREATE INDEX idx_theatres_province_name ON public.theatres USING btree (((((data -> 'address'::text) -> 'province'::text) ->> 'name'::text)));
CREATE INDEX idx_theatres_qwc_is_active ON public.theatres USING btree (qwc_is_active);
CREATE INDEX idx_theatres_tags ON public.theatres USING gin (tags);

CREATE UNIQUE INDEX company_screen_mappings_key ON public.company_screen_mappings USING btree (company_id, screen_id) WHERE (is_deleted = false);

CREATE UNIQUE INDEX idx_scheduling_times_company_id_screen_id_content_type_id ON public.scheduling_times USING btree (company_id, screen_id, content_type_id);
CREATE INDEX idx_screen_right_mappings_date_range ON public.screen_right_mappings USING gist (daterange(valid_from, valid_till));
CREATE INDEX idx_screen_right_mappings_time_range ON public.screen_right_mappings USING gist (public.tmrange(start_time, end_time));