Residential HVAC (Heat Pump) question

So it's that time of year here in Georgia where I'm sometimes using heat, A/C or having the windows open. My house has a heat pump and I noticed that when I use it in heating mode, the compressor only runs for about 5-10 seconds then kicks off and I get little to no heat from the vent registers inside. I did go out and touch the larger refrigerant line and it does get hot after it runs in that mode but still hardly any heat inside the house. If I just leave it like that it seems like eventually the electric "emergency" heater kicks on although I haven't gone in the air handler to actually check. Another weird thing is if I then switch it to A/C mode even if it's been sitting off for a long time (several hours) the compressor won't kick on. I went out to the circuit breaker and switched it off and back on, still didn't work then I turned the thermostat off then back to Cool and the compressor finally kicked on after about 5 minutes. Anyone know what could be going on before I call someone out to look at it? Or is this normal operation? This is my first time living in a place with this type of system, back in Colorado they typically used an A/C unit with a gas furnace for central heating. This is a Lennox system that was installed in 2019.