The recent batch (it was actually 8 that came in at the same time, #9 was something I was able to troubleshoot and fix myself) all say something similar to this:

Query:

SELECT `object_id`, `keyword` FROM `bx_classes_meta_keywords` WHERE `keyword` LIKE ? ORDER BY CHAR_LENGTH(`keyword`) DESC

Mysql error:

Table 'indiesel_una566.bx_classes_meta_keywords' doesn't exist

collation_connection:

utf8mb4_unicode_ci

Then the previous batch say:

Query:

SELECT * FROM `bx_classes_classes` INNER JOIN `bx_classes_meta_keywords` ON `bx_classes_meta_keywords`.`object_id`=`bx_classes_classes`.`id`WHERE 1 AND `bx_classes_classes`.`status` ='active' AND `bx_classes_classes`.`status_admin` ='active' AND `bx_classes_meta_keywords`.`keyword` ='Verified Sellers' LIMIT 0, 4

Mysql error:

Table 'indiesel_una566.bx_classes_classes' doesn't exist

collation_connection:

utf8mb4_unicode_ci

Do you need the debug backtrace and/or settings attachments too? It's all a bunch of code that seems to be related to the classes module. It seems like what's happening is people are using other parts of the site, and it's causing the site to try to find the classes module to add the connections, but connections are failing because the classes module doesn't exist.