Thank you guys for all the feedback! So I took into consideration some people in the thread said:
I first tried the original suggestion by @Nerull, I added a 1k and 100k pot in series as a dummy load, but I didn't see anything similar to what was shown in w2aew's video. The glitches sort of "flattened out" and then the output started clipping.
@rstofer and @Cerebus mentioned the 741 being used with at least ±10V, so I adjusted my PSU to 20V so the split would be -10V +10V.
@rstofer mentioned that the resistors for the voltage dividers needed to be lower so I used 1k as suggested.
These modifications didn't affect the output in any way, so finally, since I purchased these off of Ebay from a dubious chinese reseller, i'm going to take into consideration what @magic said and assume these amps are just janked clone ripoffs. I have some other amps which I want to try out, I actually got some ceramic chips from an old bag of mixmatch parts I got a while ago, so I'll try them next.