Running Micropython on Pi Pico and attempting to use the VEML7700 connected to a TCA9548a on Channel 0. Platform_Detector and Blinka src files are installed. Other adafruit libraries are working fine. As you can see in the output below my VEML6070 is communicating on channel 1 without issues.

import sys
import time
import board
import busio
import adafruit_tca9548a
import adafruit_veml7700
import adafruit_veml6070
# Setting Sampling Frequency
sample_half_sec = time.ticks_ms()
sample_sec = time.ticks_ms()
i2c = busio.I2C(board.GP5, board.GP4, frequency=400000)
tca = adafruit_tca9548a.TCA9548A(i2c)
for channel in range(8):
    if tca[channel].try_lock():
        print("Channel {}:".format(channel), end="")
        addresses = tca[channel].scan()
        print([hex(address) for address in addresses if address != 0x70])
        tca[channel].unlock()
# UV SENSOR
uv = adafruit_veml6070.VEML6070(tca[1])
# Alternative constructors with parameters
# uv = adafruit_veml6070.VEML6070(tca[1], 'VEML6070_1_T')
# uv = adafruit_veml6070.VEML6070(tca[1], 'VEML6070_HALF_T', True)
def UV_DATA():
    uv_raw = uv.uv_raw
    risk_level = uv.get_index(uv_raw)
    print("Reading: {0} | Risk Level: {1}".format(uv_raw, risk_level))
# LUX SENSOR
luxsensor = adafruit_veml7700.VEML7700(tca[0])
print("Light Integration Time:", luxsensor.light_integration_time)
print("Ambient Light:", luxsensor.lux)
def LUX_DATA():
    print("Ambient Light:", luxsensor.lux)
while True:
    if (time.ticks_ms() - sample_half_sec > 500):
        sample_half_sec = time.ticks_ms()
    if (time.ticks_ms() - sample_sec > 1000):
        UV_DATA()
        LUX_DATA()
        sample_sec = time.ticks_ms()

REPL OUTPUT:
MicroPython v1.18 on 2022-01-17; Raspberry Pi Pico with RP2040
Type "help()" for more information.

%Run -c $EDITOR_CONTENT
Channel 0:['0x10']
Channel 1:['0x38', '0x39']
Channel 2:['0x77']
Channel 3:[]
Channel 4:['0x61']
Channel 5:[]
Channel 6:[]
Channel 7:[]
Reading: 0 | Risk Level: LOW
Traceback (most recent call last):
File "", line 35, in
File "/lib/adafruit_veml7700.py", line 197, in init
RuntimeError: Unable to enable VEML7700 device

I've flashed the same Pico with CircuitPython and the sensor works properly with the same library.