Cannot access the plugins Settings

[colin-oos]

I'm unable to navigate to the settings page for this plugin and therefore cannot manage the plugin at all. I'm on Craft Pro 3.5.7. When I go to the settings page, I get the following PHP error:

SQLSTATE[42883]: Undefined function: 7 ERROR: operator does not exist: boolean = integer
LINE 4: ...tionId" = "sections"."id" AND "sections_sites"."hasUrls" = 1
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
The SQL being executed was: SELECT "sections"."id", "sections"."structureId", "sections"."name", "sections"."handle", "sections"."type", count(DISTINCT entries.id) AS "entryCount", count(DISTINCT elements.id) AS "elementCount", "sitemap_entries"."id" AS "sitemapEntryId", "sitemap_entries"."changefreq" AS "changefreq", "sitemap_entries"."priority" AS "priority"
FROM "sections" "sections"
LEFT JOIN "structures" "structures" ON "structures"."id" = "sections"."structureId"
INNER JOIN "sections_sites" "sections_sites" ON "sections_sites"."sectionId" = "sections"."id" AND "sections_sites"."hasUrls" = 1
LEFT JOIN "entries" "entries" ON "sections"."id" = "entries"."sectionId"
LEFT JOIN "elements" "elements" ON "entries"."id" = "elements"."id" AND "elements"."enabled" = 1
LEFT JOIN "dolphiq_sitemap_entries" "sitemap_entries" ON "sections"."id" = "sitemap_entries"."linkId" AND "sitemap_entries"."type" = "section"
WHERE "sections"."dateDeleted" IS NULL
GROUP BY "sections"."id"
ORDER BY "type"
Error Info: Array
(
[0] => 42883
[1] => 7
[2] => ERROR: operator does not exist: boolean = integer
LINE 4: ...tionId" = "sections"."id" AND "sections_sites"."hasUrls" = 1
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
)
↵
Caused by: PDOException

SQLSTATE[42883]: Undefined function: 7 ERROR: operator does not exist: boolean = integer
LINE 4: ...tionId" = "sections"."id" AND "sections_sites"."hasUrls" = 1
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.

in /home/ubuntu/craft/vendor/yiisoft/yii2/db/Command.php at line 1293

[ryotadialpad]

I'm getting exact same error message when I tried to visit /settings/sitemap from plugin page

Craft CMS 3.4.15
PostgreSQL 11.4