Yes it very well can cause the modem to go intermittent. Even if it appears online through the light pattern and within the cable modem itself, you could loose connectivity to headend you're connected to and/or the modem could loose it's lock on the headend.
What are the signals you have currently if you log into the modem?
When you say 'Look Fine' ... what exactly do you mean by that? They have particular requirements to stay connected online. Can youpost a screen cap of what they look like, the SNR, etc from the mdm logs to make sure.
And by speed booster, are you taking about an In-Line Amplifier? Aka. Signal Booster?
Depends what the actual issue is. Tx (Upstream) Power levels need to be Between 36 DBmV and 54 DBmV for Docsis 3.0 Specs, and Rx (Downstream) Power levels need to be between 10 DBmV and -10DBmV.
If they're too high (I've seen 56+ easily cause the modem to reboot on its own or loose RF connectivity), or even if they're too high @ the tap and are showing ~25-30 for the Tx levels on the modem, you may need an attenuator, or an In-Line Amp or a tech may need to install a splitter & hook the mdm up to a powered leg on the output side.
Also when you look at the logs check the SNR, Docsis 3.0 Specs say it needs to be above 32. Anything around 32, or especially lower, could have some noise from the street / tap / plant coming in the line and it needs to be addressed.