IBS-P01R continually disconnects from monitor

I pair the two, temperature shows on the monitor and later, the monitor shows 3 dashes.
This has happened over and over.
The sensor and monitor are no more than 15 feet apart

Please check whether the battery power of the transmitter and receiver is sufficient. Are the batteries rechargeable or non-rechargeable? Are the transmitter and receiver intact?
Is there an obstacle between the transmitter and receiver? If the transmitter is placed next to the receiver and re-paired for testing, will it also disconnect?

Batteries are fresh, no obstacles other than a standard house wall.
No idea, I put the sensor in the pool where it belongs. This is not a new unit, had for a year or two, this just started

Do you mean there is no problem to use the same brand of batteries in the same position as before?
If yes, please contact support@inkbird.com for after sales, please provide the link of this post and order information for them to process quickly.