FIFO issue at startup

We recently always get this after startup. Needs fixed.

- Checking elinks
Both elinks (0 and 2) are locked.
uhal UDP error in FIFO.read_block, block size is 250
---------------------------------------------------------------------------
exception                                 Traceback (most recent call last)
File ~/ETROC2_Test_Stand/module_test_sw/test_ETROC.py:354
    351     print(red('No elink is locked.'))
    353 fifo.send_l1a(10)
--> 354 _ = fifo.pretty_read(df)
    355 etroc.reset()
    357 print("\n - Getting internal test data")

File ~/ETROC2_Test_Stand/module_test_sw/tamalero/FIFO.py:214, in FIFO.pretty_read(self, df, dispatch, raw)
    213 def pretty_read(self, df, dispatch=True, raw=False):
--> 214     merged = merge_words(self.read(dispatch=dispatch))
    215     if raw:
    216         return merged

File ~/ETROC2_Test_Stand/module_test_sw/tamalero/FIFO.py:158, in FIFO.read(self, dispatch, verbose)
    155 data = []
    156 while self.get_occupancy()>0:
    157     # FIXME checking get_occupancy all the time is slow, but this is at least not broken.
--> 158     data += self.read_block(250, dispatch=dispatch).value()
    160 #if (num_blocks_to_read or last_block):
    161 #    if dispatch:
    162 #        #while self.get_occupancy()>0:
   (...)
    184 #        for read in reads:
    185 #            data += read.value()
    186 return data

File ~/ETROC2_Test_Stand/module_test_sw/tamalero/FIFO.py:140, in FIFO.read_block(self, block, dispatch)
    138 if dispatch:
    139     reads = self.rb.kcu.hw.getNode("DAQ_RB0").readBlock(block)
--> 140     self.rb.kcu.hw.dispatch()
    141     return reads
    142 else:

exception: Bad response code (0x6 = 'bus timeout on read') received for Non-incrementing read at base address 0x100000 (node "TOP.DAQ_RB0.FIFO").  URI: "chtcp-2.0://localhost:10203?target=192.168.0.10:50001". Sent/received headers: 0x2f9cfa2f / 0x2f9c0026 (transaction 1/1 bytes into IPbus payload)

Can be recovered by running

fifo.reset()
fifo.send_l1a(5)
fifo.pretty_read(df)
fifo.reset()

But needs proper solution