[WIRELESS ENGINEER]

Using indoor antennas these days is difficult since everything electronic radiates rf interference at various levels and frequencies
Routers, cable modems, roku boxes, led lights, and even the TV itself all generate rf at some level
So it is always better to use an outside antenna without a preamp if you can but even an indoor antenna without a preamp may work
TV tuners have very poor selectivity and so they can easily be "desensed" by out of band interference like two way radios, LTE tower sites etc so if preamps become unavoidable they must filter these sources out or they will simply make this worse

Identifying the source can be difficult but you can simply power off the possible offending electronics one at a time till you find it
I have seen window air conditioners, stoves, and refrigerators with electronic controls generate high levels of rf noise

I have a Motorola communications service monitor with a rf spectrum analizer and an Anritsu site master that I use to track down interference but even with those, it can be difficult