does throttling idle websites happen?

Thank you so much for your time.

I have not included any URL’s because it doesn’t matter which site, and I’m trying to let them “go dormant” again to show someone.
If you access it, chances are I’m working on it and it only happens after the site has had no activity for hours.

I am on shared small business plan hosting at Temok, linux, with various WordPress themes and plugins, with or without cache plugins (currently without, mainly, but vary pared down Astra, for example, incomplete sites, with a 90kB background and nothing else).

Here is what happens once a day, every day:

My several addon domain’s WP sites on Shared Hosting at Temok (all except the hosting plan’s main domain’s site for some reason) – they seem to “go to sleep” after no visitors (or me) access them for hours.

After being idle for a long time with no visitors, only the very first request to load the site takes absolutely forever (for anyone anywhere regardless of device or local cache status).
Occasionally the one slightly developed site with some audio content says “Error Connecting to Database” (just the once, first load, then is fine after that).

Then, after you “wake up” each site by visiting it or logging into WP, either one, that site will start loading fine for the remainder of my activity for the night… every…night….

This can’t be a local browser cache thing.
It happens exactly the same with full cache, freshly emptied cache, or single instance Incognito Chrome.

In fact it can take forever with my cache not empty, then be fine for the rest of the night with an cleared cache or single incognito instance (because the site is now “awake” at the server, seemingly).

I got a reply from Temok saying the sites load fine, then I pointed out it does no good to check after I’m messing with the sites because it only happens once a day after WP idle time. So then they said:

“It seems the issue was due to PHP Warning: mysqli_real_connect(): (HY000/1040): Too many connections in /home/wetfleec/public_html/wp-includes/wp-db.php on line 1653 which in return caused high CPU usage on your account which was slowing down the websites.
Your MySQL database allows so many connections at the same time. If you connect to MySQL via PHP, then you generally open a new connection every time a page on your site loads. So if you’ve got too much traffic to your site this can cause this issue. “

But this doesn’t sound right because these sites are extremely obscure and even currently set to be ignored by search engines. I can check stats.. and no crowd (or guy with 20 windows open) is visiting right when I log in for the first time all day and suddenly leaving every night after that. I open maybe 4 or 5 windows tops and can have only one open, first of the day, when this happens.

Someone suggested a form of throttling by the host… but what kind of sense does that make (that’s a real question, not rhetorical)… isn’t that backwards?
Wouldn’t you throttle something actively using resources, not steal bandwidth or even CPU from something that’s not using it or being visited?

Do idle websites use resources that can be borrowed unscrupulously?? Could the host or even someone else on my shared hosting IP be stealing resources from idle sites to try to fly under the radar and then back off after the victim’s being visited?

This has been happening for a looong time, to myself and the other family member (or odd friend) visiting or working on my very un-visited sites (un-visited by users or bots either one… 4 or 5 brief visitors one evening, who saw me on social media, made a stats spike a mile high, lol).

Is there some code or setting somewhere that can cause this, that I can change?
I can load WordPress caching plugins again (I hadn’t yet since the sites are so minimal just yet) but I’m pretty sure it made no difference and I had separate issues with them and this version of PHP.
These sites include very unfinished, stripped down Astra sites even doing this.
Only thing of any size at all is the 90kB background and nothing else but a header and a paragraph.

Again, a URL would be highly ambiguous, this is a general no-matter-what issue.
I’m wondering if I can trust my host, too.
I have had very very good experiences with them being very helpful in the past.

Thank you for your time
Jeff in rural FL, US
doing the best I can with my small budget and low-intermediate, lay web hosting experience.