Use of Product Group filter on Website results in Internal Server Error 500

I am facing an issue using Item Group filter on the Products page (all-products) of the Website. Upon selecting any of the item group from the list to filter products, the URL in address bar is updated however the product listing is not updated till the page is refreshed. Examining the Console I noticed a 500 Internal Server Error with an exception as below. Clearing the filters (either using the Clear link or by unchecking any filter selection), all products are listed on the page and no exception is raised.

Software Info:
erpnext 13.x.x-develop
frappe 13.x.x-develop

Exception in Console:
website.js:160 Syntax error in query:
select name, *
from tabItem Group
where coalesce(tabItem Group.name, ‘’) in (‘MIRRORS’)

		 order by `tabItem Group`.`modified` DESC

Traceback (most recent call last):
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/app.py”, line 63, in application
response = frappe.handler.handle()
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/handler.py”, line 31, in handle
data = execute_cmd(cmd)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/handler.py”, line 67, in execute_cmd
return frappe.call(method, **frappe.form_dict)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/init.py”, line 1179, in call
return fn(*args, **newargs)
File “/home/muhannad/mcrm-bench/apps/erpnext/erpnext/portal/product_configurator/utils.py”, line 93, in get_products_html_for_website
set_item_group_filters(field_filters)
File “/home/muhannad/mcrm-bench/apps/erpnext/erpnext/portal/product_configurator/utils.py”, line 105, in set_item_group_filters
field_filters[‘item_group’] = [ig[0] for ig in get_child_groups(field_filters[‘item_group’])]
File “/home/muhannad/mcrm-bench/apps/erpnext/erpnext/setup/doctype/item_group/item_group.py”, line 214, in get_child_groups
item_group = frappe.get_doc(“Item Group”, item_group_name)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/init.py”, line 857, in get_doc
doc = frappe.model.document.get_doc(*args, **kwargs)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/model/document.py”, line 72, in get_doc
return controller(*args, **kwargs)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/website/website_generator.py”, line 16, in init
super(WebsiteGenerator, self).init(args, **kwargs)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/model/document.py”, line 110, in init
self.load_from_db()
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/model/document.py”, line 151, in load_from_db
d = frappe.db.get_value(self.doctype, self.name, "
", as_dict=1, for_update=self.flags.for_update)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/database/database.py”, line 398, in get_value
order_by, cache=cache, for_update=for_update)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/database/database.py”, line 430, in get_values
out = self._get_value_for_many_names(doctype, filters, fieldname, debug=debug)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/database/database.py”, line 607, in _get_value_for_many_names
debug=debug, as_list=1)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/database/database.py”, line 527, in get_all
return frappe.get_all(*args, **kwargs)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/init.py”, line 1439, in get_all
return get_list(doctype, *args, **kwargs)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/init.py”, line 1412, in get_list
return frappe.model.db_query.DatabaseQuery(doctype).execute(args, **kwargs)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/model/db_query.py”, line 104, in execute
result = self.build_and_run()
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/model/db_query.py”, line 142, in build_and_run
update=self.update, ignore_ddl=self.ignore_ddl)
File “/home/muhannad/mcrm-bench/apps/frappe/frappe/database/database.py”, line 144, in sql
self._cursor.execute(query)
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/cursors.py”, line 148, in execute
result = self._query(query)
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/cursors.py”, line 310, in _query
conn.query(q)
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/connections.py”, line 548, in query
self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/connections.py”, line 775, in _read_query_result
result.read()
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/connections.py”, line 1156, in read
first_packet = self.connection._read_packet()
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/connections.py”, line 725, in _read_packet
packet.raise_for_error()
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/protocol.py”, line 221, in raise_for_error
err.raise_mysql_exception(self._data)
File “/home/muhannad/mcrm-bench/env/lib/python3.6/site-packages/pymysql/err.py”, line 143, in raise_mysql_exception
raise errorclass(errno, errval)
pymysql.err.ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '
\n\t\t\tfrom tabItem Group\n\t\t\twhere coalesce(tabItem Group.name, ‘’) in (‘MI…’ at line 1")