I think it’s not problem in this case. Router located in area of coverage of two Nodes-B, but attached to Cell1 where best signal strength available. It can be problem if both cells work on same frequencies but I think this is near zero chance of such occasions - radio planers in mobile operators must not allow this.
Can you provide additional information about your problem:
1) Losses happened all the day or only some hours? (Maybe there is some congestion problem on radio network?)
2) How much traffic goes through cellular interface during you observe loses? (Maybe your mobile operator can’t grant you such throughput). Look at the show cellular 0 connection output as well to verify your service parameters.
3) Monitor output of show cellular 0 network during periods of loss. Does your router keep same connection to same cell during this event or it flaps between cells?