Edge feature that keeps unloading previously loaded pages

I am using this Edge copy in a VMware environment.
I actually do not know if this issue is due to a feature in MS Edge, so I am also asking if there is such a thing. The behaviour is as follows: I open about 15 tabs. I give each the time they need to load the whole page. Then I use them all constantly, with a wait of about 30 seconds max. However, if I take about 2 minutes before I go back to any of those pages, then they behave as if I am opening it for the 1st time. As if nothing was previously loaded. Very much defeats the whole purpose of opening them in advance. I need them for my job, I take calls on the phone and I need these pages to be available at a second's notice. Therefore, having to wait multiple times throughout my shift for them to be done reloading, is extremely frustrating, to say the least.
I hope someone knows of a setting in Edge that I can change to improve on this issue.
Thank you in advance for your time.

J.

T.O, that was super fast!
I have only disabled those Sleeping tabs so far. I will disable the Efficiency mode too asap. I hope this last one is the reason why is doing that. I'll let you know.
Thank you T.O. :)

DPC

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I was able to check now. Unfortunately I had already disabled the Efficiency and Efficiency Gaming modes too
I just disabled Startup Boost, I do not see how that could help, but I just can't see anything else.
Do you think the problem is VMware instead?
After all, I do get the same behaviour with Google Chrome too.